Communication Method, Network Device, User Equipment, and Communications System

ABSTRACT

The present disclosure discloses a communication method, a network device, user equipment, and a communications system. The communication method includes determining, by a network device, to allocate a first secondary cell group (SCG) to user equipment, and sending, by the network device, first configuration indication information to the user equipment, where the first configuration indication information indicates at least one type of the following configuration transmitting uplink control information related to a cell in the first SCG by using a physical uplink control channel (PUCCH) of a first cell, where the first cell belongs to a second SCG of the user equipment, or processing data transmission on at least one cell in the first SCG by using a layer 2 functional entity located in the second SCG. The communication method disclosed in the present disclosure can reduce complexity of UE.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/662,954, filed on Jul. 28, 2017, which is a continuation ofInternational Application No. PCT/CN2015/072017, filed on Jan. 30, 2015,which are incorporated by reference.

TECHNICAL FIELD

Embodiments of the present disclosure relate to the communicationsfield, and more specifically, to a communication method, a networkdevice, user equipment, and a communications system.

BACKGROUND

A carrier aggregation (CA) technology is mainly to aggregate multiplecomponent carriers (CC) into one carrier with higher bandwidth, so as tosupport high-speed data transmission. In current Long Term Evolution(LTE) carrier aggregation, a maximum of eight carriers can beaggregated. To enable a user equipment (UE) to aggregate CC on differentbase stations (for example, a macro base station and a micro basestation), to further obtain a higher data transmission rate, a dualconnectivity (DC) technology can be introduced. A main idea of the DCtechnology is to aggregate carriers on different base stations connectedby a non-ideal backhaul link (backhaul). In DC, two cell groups orcomponent carrier groups (CC group) are configured for one UE. One groupis a master cell group (MCG), and the other group is a secondary cellgroup (SCG). Specific concepts are described as follows.

A MCG is a cell group that is associated with a master base station(MeNB) and includes a primary cell (PCell) and zero or at least onesecondary cell (SCell).

A SCG is a cell group that is associated with a secondary base station(SeNB) and includes a primary secondary cell (PSCell) and zero or atleast one secondary cell.

A PCell is a cell that establishes a Radio Resource Control (RRC)connection to UE. The PCell is responsible for providing asecurity-related parameter, and a physical uplink control channel(PUCCH) resource is configured for the PCell.

A PSCell is a secondary cell that is included in a SCG and for which aPUCCH resource is configured.

A PUCCH is mainly used to transmit hybrid automatic repeatrequest-acknowledgement (HARQ-ACK) information, channel stateinformation (CSI), a scheduling request (SR), and the like.

Except for the foregoing PCell and PSCell, no PUCCH resource isconfigured for other cells (that is, SCells) included in an MCG and anSCG.

FIG. 1 shows an example of a typical DC scenario. UE establishes aconnection to both an MeNB and an SeNB, and the MeNB communicates withthe SeNB by using an X2 interface. An MCG includes cells associated withthe MeNB a PCell, an SCell 1, and an SCell 2. An SCG includes cellsassociated with the SeNB a PSCell and an SCell 3. The MCG and the SCGrespectively correspond to different intermediate keys (Secondary key)and layer 2 functional entities, and PUCCH resources are respectivelyconfigured for the PCell and the PSCell. In addition, when the UEperforms data transmission to the MeNB or the SeNB, the UE may establisha bearer to the MeNB or the SeNB and encrypt, by using a securityconfiguration parameter (for example, an intermediate key) of a cellgroup corresponding to the bearer, data transmitted over the bearer.Alternatively, the UE may establish a split (split) bearer to the MeNBand the SeNB. In this case, a part of a data packet is transmitted byusing the MCG, and the other part is transmitted by using the SCG, anddata transmitted by the MCG and data transmitted by the SCG are bothencrypted by using a security configuration parameter corresponding tothe MCG.

To further improve a data transmission rate, a massive carrieraggregation technology is introduced, to implement carrier aggregationof more CC, for example, carrier aggregation of 32 CC. However,according to an existing DC technology, if a large quantity of CC areintroduced, an independent PUCCH, layer 2 functional entity, andintermediate key need to be configured for each SCG, and a quantity ofparameters that UE needs to maintain abruptly increases. As a result,complexity of a function of the UE is increased.

SUMMARY

Embodiments of the present disclosure provide a communication method, anetwork device, user equipment, and a communications system, so as toreduce complexity of UE.

According to a first aspect, an embodiment of the present disclosureprovides a communication method, including determining, by a networkdevice, to allocate a first SCG to user equipment, and sending, by thenetwork device, first configuration indication information to the userequipment, where the first configuration indication information is usedto indicate at least one type of the following configurationtransmitting uplink control information related to a cell in the firstSCG by using a PUCCH of a first cell, where the first cell belongs to asecond SCG of the user equipment, or processing data transmission on atleast one cell in the first SCG by using a layer 2 functional entitylocated in the second SCG.

In a first possible implementation, the first cell is a PSCell in thesecond SCG of the user equipment.

With reference to the foregoing possible implementation, in a secondpossible implementation, the first configuration indication informationincludes at least one of the following information identificationinformation of the second SCG of the user equipment or identificationinformation of the first cell.

With reference to the foregoing possible implementations, in a thirdpossible implementation, the layer 2 functional entity includes at leastone of a Media Access Control entity, a Radio Link Control entity, or aPacket Data Convergence Protocol entity.

With reference to the foregoing possible implementations, in a fourthpossible implementation, the first configuration indication informationis further used to indicate establishing, in the second SCG of the userequipment, at least one of a Packet Data Convergence Protocol entity ora Radio Link Control entity that corresponds to a bearer of the firstSCG, and the processing data transmission on at least one cell in thefirst SCG by using a layer 2 functional entity located in the second SCGincludes processing data transmission on the bearer of the first SCG byusing at least one of the Packet Data Convergence Protocol entity or theRadio Link Control entity that is established in the second SCG and thatcorresponds to the bearer.

With reference to the foregoing possible implementations, in a fifthpossible implementation, the first configuration indication informationis further used to indicate establishing a split bearer of the first SCGand the second SCG and indicate a SCG, used to perform a splitoperation, in the first SCG and the second SCG.

With reference to the foregoing possible implementations, in a sixthpossible implementation, the network device is a MeNB, the userequipment has at least two serving base stations including the MeNB anda first SeNB, and the first SCG is associated with the first SeNB,before the sending, by the network device, first configurationindication information to the user equipment, the method furtherincludes sending, by the MeNB, second configuration indicationinformation to the first SeNB, where the second configuration indicationinformation is used to indicate a configuration parameter of the firstSCG that is determined by the MeNB, and the configuration parameterincludes at least one of a PUCCH of the cell in the first SCG or a layer2 functional entity corresponding to the data transmission on the atleast one cell in the first SCG, and receiving, by the MeNB, aconfiguration response message that is sent by the first SeNB accordingto the second configuration indication information, and the sending, bythe network device, first configuration indication information to theuser equipment includes sending, by the MeNB, the first configurationindication information to the user equipment according to theconfiguration response message.

With reference to the foregoing possible implementation, in a seventhpossible implementation, the configuration response message carries aconfiguration parameter of the first SCG that is determined by the firstSeNB according to the second configuration indication information, andthe sending, by the network device, the first configuration indicationinformation to the user equipment according to the configurationresponse message includes determining, by the MeNB, at least one type ofthe following configuration according to the configuration responsemessage transmitting the uplink control information of the cell in thefirst SCG by using the PUCCH of the first cell, or processing the datatransmission on the at least one cell in the first SCG by using thelayer 2 functional entity located in the second SCG.

With reference to the foregoing possible implementations, in an eighthpossible implementation, the first configuration indication informationis further used to indicate at least one type of the followingconfiguration, in a data transmission process in the at least one cellin the first SCG, generating an encryption key by using a securityconfiguration parameter of the second SCG of the user equipment, or in adata transmission process in the at least one cell in the first SCG,performing uplink timing adjustment by using a timing advance value ofthe second SCG of the user equipment.

According to a second aspect, another communication method is provided,including determining, by a network device, to allocate a first cellgroup to user equipment, where the first cell group is a SCG, andsending, by the network device, first configuration indicationinformation to the user equipment, where the first configurationindication information is used to indicate at least one type of thefollowing configuration, in a data transmission process in at least onecell in the first cell group, generating an encryption key by using asecurity configuration parameter of a second cell group of the userequipment, or in a data transmission process in at least one cell in thefirst cell group, performing uplink timing adjustment by using a timingadvance value of a second cell group of the user equipment.

In a first possible implementation, the first cell group and the secondcell group of the user equipment are associated with a same serving basestation of the user equipment.

With reference to the foregoing possible implementation, in a secondpossible implementation, the second cell group of the user equipment isa MCG or a SCG.

With reference to the foregoing possible implementations, in a thirdpossible implementation, the security configuration parameter includesat least one of the following parameters a SCG counter, a SCGintermediate key, an index value of a SCG intermediate key, or a serialnumber of a SCG intermediate key.

With reference to the foregoing possible implementations, in a fourthpossible implementation, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, generating an encryption key byusing a security configuration parameter of a second cell group of theuser equipment includes. the first configuration indication informationis used to indicate processing data transmission on the at least onecell in the first cell group by using a Packet Data Convergence Protocolentity located in the second cell group.

With reference to the foregoing possible implementations, in a fifthpossible implementation, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate that the first cell group of the user equipment andthe second cell group of the user equipment belong to a same timingadvance group (TAG), or the first configuration indication informationis used to indicate that a PSCell in the first cell group of the userequipment and a PSCell or a PCell in the second cell group of the userequipment belong to a same TAG.

With reference to the foregoing possible implementations, in a sixthpossible implementation, the network device is a first SeNB associatedwith both the first cell group and the second cell group, and the userequipment has at least two serving base stations including a MeNB andthe first SeNB, before the sending, by the network device, firstconfiguration indication information to the user equipment, the methodfurther includes receiving, by the network device, second configurationindication information sent by the MeNB, where the second configurationindication information is used to instruct the first SeNB to allocatethe first cell group to the user equipment, and the determining, by anetwork device, to allocate a first cell group to user equipmentincludes determining, by the network device according to the secondconfiguration indication information, to allocate the first cell groupto the user equipment.

According to a third aspect, another communication method is provided,including receiving, by user equipment, first configuration indicationinformation sent by a network device, where the first configurationindication information is used to indicate at least one type of thefollowing configuration transmitting uplink control information relatedto a cell in a first SCG of the user equipment by using a PUCCH of afirst cell, where the first cell belongs to a second SCG of the userequipment, or processing data transmission on at least one cell in afirst SCG of the user equipment by using a layer 2 functional entitylocated in the second SCG, and configuring, by the user equipment, thefirst SCG of the user equipment according to the first configurationindication information.

In a first possible implementation, the first cell is a PSCell in thesecond SCG of the user equipment.

With reference to the foregoing possible implementation, in a secondpossible implementation, the first configuration indication informationincludes at least one of the following information identificationinformation of the second SCG of the user equipment or identificationinformation of the first cell.

With reference to the foregoing possible implementations, in a thirdpossible implementation, the layer 2 functional entity includes at leastone of a Media Access Control entity, a Radio Link Control entity, or aPacket Data Convergence Protocol entity.

With reference to the foregoing possible implementation, in a fourthpossible implementation, the first configuration indication informationis further used to indicate establishing, in the second SCG, at leastone of a Packet Data Convergence Protocol entity or a Radio Link Controlentity that corresponds to a bearer of the first SCG, and the processingdata transmission on at least one cell in a first SCG by using a layer 2functional entity established in the second SCG of the user equipmentincludes processing data transmission on the bearer of the first SCG byusing at least one of the Packet Data Convergence Protocol entity or theRadio Link Control entity that is established in the second SCG and thatcorresponds to the bearer.

With reference to the foregoing possible implementations, in a fourthpossible implementation, the first configuration indication informationis further used to indicate establishing a split bearer of the first SCGand the second SCG and indicate a SCG, used to perform a splitoperation, in the first SCG and the second SCG.

With reference to the foregoing possible implementations, in a fifthpossible implementation, the first configuration indication informationis further used to indicate at least one type of the followingconfiguration, in a data transmission process in the at least one cellin the first SCG, generating an encryption key by using a securityconfiguration parameter of the second SCG of the user equipment, or in adata transmission process in the at least one cell in the first SCG,performing uplink timing adjustment by using a timing advance value ofthe second SCG of the user equipment.

According to a fourth aspect, another communication method is provided,including receiving, by user equipment, first configuration indicationinformation sent by a network device, where the first configurationindication information is used to indicate at least one type of thefollowing configuration, in a data transmission process in at least onecell in a first cell group of the user equipment, generating anencryption key by using a security configuration parameter of a secondcell group of the user equipment, or in a data transmission process inat least one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment, and configuring, by the user equipment, the first cellgroup according to the first configuration indication information.

In a first possible implementation, the first cell group of the userequipment and the second cell group of the user equipment are associatedwith a same serving base station of the user equipment.

With reference to the foregoing possible implementation, in a secondpossible implementation, the second cell group of the user equipment isa MCG or a SCG.

With reference to the foregoing possible implementations, in a thirdpossible implementation, the security configuration parameter includesat least one of the following parameters a SCG counter, a SCGintermediate key, an index value of a SCG intermediate key, or a serialnumber of a SCG intermediate key.

With reference to the foregoing possible implementations, in a fourthpossible implementation, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, generating an encryption key byusing a security configuration parameter of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate processing data transmission on the at least onecell in the first cell group by using a Packet Data Convergence Protocolentity located in the second cell group.

With reference to the foregoing possible implementations, in a fifthpossible implementation, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate that the first cell group of the user equipment andthe second cell group of the user equipment belong to a same TAG, or thefirst configuration indication information is used to indicate that aPSCell in the first cell group of the user equipment and a PSCell or aPCell in the second cell group of the user equipment belong to a sameTAG.

With reference to the foregoing possible implementations, in a sixthpossible implementation, the method further includes receiving, by theuser equipment, second configuration indication information sent by thenetwork device, where the second configuration indication information isused to indicate a random access resource allocated by the networkdevice to the second cell group of the user equipment, performing, bythe user equipment, a random access process in the second cell groupaccording to the second configuration indication information, to obtaina timing advance value of the second cell group, and communicating, bythe user equipment, with the serving base station of the user equipmentin the first cell group according to the timing advance value of thesecond cell group.

According to a fifth aspect, a network device is provided, including adetermining unit configured to determine to allocate a first SCG to userequipment, and a sending unit configured to send first configurationindication information to the user equipment, where the firstconfiguration indication information is used to indicate at least onetype of the following configuration transmitting uplink controlinformation related to a cell in the first SCG by using a PUCCH of afirst cell, where the first cell belongs to a second SCG of the userequipment, or processing data transmission on at least one cell in thefirst SCG by using a layer 2 functional entity located in the secondSCG.

In a first possible implementation, the first cell is a PSCell in thesecond SCG of the user equipment.

With reference to the foregoing possible implementation, in a secondpossible implementation, the first configuration indication informationincludes at least one of the following information identificationinformation of the second SCG of the user equipment or identificationinformation of the first cell.

With reference to the foregoing possible implementations, in a thirdpossible implementation, the layer 2 functional entity includes at leastone of a Media Access Control entity, a Radio Link Control entity, or aPacket Data Convergence Protocol entity.

With reference to the foregoing possible implementations, in a fourthpossible implementation, the first configuration indication informationis further used to indicate establishing, in the second SCG of the userequipment, at least one of a Packet Data Convergence Protocol entity ora Radio Link Control entity that corresponds to a bearer of the firstSCG, and the processing data transmission on at least one cell in thefirst SCG by using a layer 2 functional entity located in the second SCGincludes processing data transmission on the bearer of the first SCG byusing at least one of the Packet Data Convergence Protocol entity or theRadio Link Control entity that is established in the second SCG and thatcorresponds to the bearer.

With reference to the foregoing possible implementations, in a fifthpossible implementation, the first configuration indication informationis further used to indicate establishing a split bearer of the first SCGand the second SCG and indicate a SCG, used to perform a splitoperation, in the first SCG and the second SCG.

With reference to the foregoing possible implementations, in a sixthpossible implementation, the network device is a MeNB, the userequipment has at least two serving base stations including the MeNB anda first SeNB, and the first SCG is associated with the first SeNB, thesending unit is further configured to, before sending the firstconfiguration indication information to the user equipment, send secondconfiguration indication information to the first SeNB, where the secondconfiguration indication information is used to indicate a configurationparameter of the first SCG that is determined by the MeNB, and theconfiguration parameter includes at least one of a PUCCH of the cell inthe first SCG or a layer 2 functional entity corresponding to the datatransmission on the at least one cell in the first SCG, the MeNB furtherincludes a second receiving unit configured to receive a configurationresponse message that is sent by the first SeNB according to the secondconfiguration indication information sent by the sending unit, and thesending unit is specifically configured to send the first configurationindication information to the user equipment according to theconfiguration response message received by the second receiving unit.

With reference to the foregoing possible implementations, in a seventhpossible implementation, the configuration response message is used toindicate a configuration parameter of the first SCG that is determinedby the first SeNB according to the second configuration indicationinformation, and the sending unit includes a determining subunitconfigured to determine at least one type of the following configurationaccording to the configuration response message received by the secondreceiving unit transmitting the uplink control information of the cellin the first SCG by using the PUCCH of the first cell, or processing thedata transmission on the at least one cell in the first SCG by using thelayer 2 functional entity located in the second SCG.

With reference to the foregoing possible implementations, in an eighthpossible implementation, the first configuration indication informationis further used to indicate at least one type of the followingconfiguration, in a data transmission process in the at least one cellin the first SCG, generating an encryption key by using a securityconfiguration parameter of the second SCG of the user equipment, or in adata transmission process in the at least one cell in the first SCG,performing uplink timing adjustment by using a timing advance value ofthe second SCG of the user equipment.

According to a sixth aspect, another network device is provided,including a determining unit configured to determine to allocate a firstcell group to user equipment, where the first cell group is a SCG, and asending unit configured to send first configuration indicationinformation to the user equipment, where the first configurationindication information is used to indicate at least one type of thefollowing configuration, in a data transmission process in at least onecell in the first cell group, generating an encryption key by using asecurity configuration parameter of a second cell group of the userequipment, or in a data transmission process in at least one cell in thefirst cell group, performing uplink timing adjustment by using a timingadvance value of a second cell group of the user equipment.

In a first possible implementation, the first cell group and the secondcell group are associated with a same serving base station of the userequipment.

With reference to the foregoing possible implementation, in a secondpossible implementation, the second cell group of the user equipment isa MCG or a SCG.

With reference to the foregoing possible implementations, in a thirdpossible implementation, the security configuration parameter includesat least one of the following parameters a SCG counter, a SCGintermediate key, an index value of a SCG intermediate key, or a serialnumber of a SCG intermediate key.

With reference to the foregoing possible implementations, in a fourthpossible implementation, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, generating an encryption key byusing a security configuration parameter of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate processing data transmission on the at least onecell in the first cell group by using a Packet Data Convergence Protocolentity located in the second cell group.

With reference to the foregoing possible implementations, in a fifthpossible implementation, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate that the first cell group of the user equipment andthe second cell group of the user equipment belong to a same TAG, or thefirst configuration indication information is used to indicate that aPSCell in the first cell group of the user equipment and a PSCell or aPCell in the second cell group of the user equipment belong to a sameTAG.

With reference to the foregoing possible implementations, in a sixthpossible implementation, the network device is a first SeNB associatedwith both the first cell group and the second cell group, and the userequipment has at least two serving base stations including a MeNB andthe first SeNB, the first SeNB further includes a second receiving unitconfigured to, before the sending unit sends the first configurationindication information to the user equipment, receive secondconfiguration indication information sent by the MeNB, where the secondconfiguration indication information is used to instruct the first SeNBto allocate the first cell group to the user equipment, and thedetermining unit is further configured to determine, according to thesecond configuration indication information received by the secondreceiving unit, to allocate the first cell group to the user equipment.

According to a seventh aspect, user equipment is provided, including areceiving unit configured to receive first configuration indicationinformation sent by a network device, where the first configurationindication information is used to indicate at least one type of thefollowing configuration transmitting uplink control information relatedto a cell in a first SCG of the user equipment by using a PUCCH of afirst cell, where the first cell belongs to a second SCG of the userequipment, or processing data transmission on at least one cell in afirst SCG of the user equipment by using a layer 2 functional entitylocated in the second SCG, and a configuration unit configured toconfigure the first SCG according to the first configuration indicationinformation received by the receiving unit.

In a first possible implementation, the first cell is a PSCell in thesecond SCG of the user equipment.

With reference to the foregoing possible implementation, in a secondpossible implementation, the first configuration indication informationincludes at least one of the following information identificationinformation of the second SCG of the user equipment or identificationinformation of the first cell.

With reference to the foregoing possible implementations, in a thirdpossible implementation, the layer 2 functional entity includes at leastone of a Media Access Control entity, a Radio Link Control entity, or aPacket Data Convergence Protocol entity.

With reference to the foregoing possible implementations, in a fourthpossible implementation, the first configuration indication informationis further used to indicate establishing, in the second SCG, at leastone of a Packet Data Convergence Protocol entity or a Radio Link Controlentity that corresponds to a bearer of the first SCG, and the processingdata transmission on at least one cell in a first SCG by using a layer 2functional entity established in the second SCG of the user equipmentincludes processing data transmission on the bearer of the first SCG byusing at least one of the Packet Data Convergence Protocol entity or theRadio Link Control entity that is established in the second SCG and thatcorresponds to the bearer.

With reference to the foregoing possible implementations, in a fifthpossible implementation, the first configuration indication informationis further used to indicate establishing a split bearer of the first SCGand the second SCG and indicate a SCG, used to perform a splitoperation, in the first SCG and the second SCG.

With reference to the foregoing possible implementations, in a sixthpossible implementation, the first configuration indication informationis further used to indicate at least one type of the followingconfiguration, in a data transmission process in the at least one cellin the first SCG, generating an encryption key by using a securityconfiguration parameter of the second SCG of the user equipment, or in adata transmission process in the at least one cell in the first SCG,performing uplink timing adjustment by using a timing advance value ofthe second SCG of the user equipment.

According to an eighth aspect, another user equipment is provided,including a receiving unit configured to receive first configurationindication information sent by a network device, where the firstconfiguration indication information is used to indicate at least onetype of the following configuration, in a data transmission process inat least one cell in a first cell group of the user equipment,generating an encryption key by using a security configuration parameterof a second cell group of the user equipment, or in a data transmissionprocess in at least one cell in the first cell group, performing uplinktiming adjustment by using a timing advance value of a second cell groupof the user equipment, and a configuration unit configured to configurethe first cell group according to the first configuration indicationinformation received by the receiving unit.

In a first possible implementation, the first cell group and the secondcell group are associated with a same serving base station of the userequipment.

With reference to the foregoing possible implementation, in a secondpossible implementation, the second cell group of the user equipment isa MCG or a SCG.

With reference to the foregoing possible implementations, in a thirdpossible implementation, the security configuration parameter includesat least one of the following parameters a SCG counter, a SCGintermediate key, an index value of a SCG intermediate key, or a serialnumber of a SCG intermediate key.

With reference to the foregoing possible implementations, in a fourthpossible implementation, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, generating an encryption key byusing a security configuration parameter of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate processing data transmission on the at least onecell in the first cell group by using a Packet Data Convergence Protocolentity located in the second cell group.

With reference to the foregoing possible implementations, in a fifthpossible implementation, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate that the first cell group of the user equipment andthe second cell group of the user equipment belong to a same TAG, or thefirst configuration indication information is used to indicate that aPSCell in the first cell group of the user equipment and a PSCell or aPCell in the second cell group of the user equipment belong to a sameTAG.

With reference to the foregoing possible implementations, in a sixthpossible implementation, the receiving unit is further configured toreceive second configuration indication information sent by the networkdevice, where the second configuration indication information is used toindicate a random access resource allocated by the network device to thesecond cell group of the user equipment, and the user equipment furtherincludes a random access unit configured to perform a random accessprocess in the second cell group according to the second configurationindication information received by the receiving unit, to obtain atiming advance value of the second cell group, and a communications unitconfigured to communicate with the serving base station of the userequipment in the first cell group according to the timing advance valueof the second cell group that is obtained by the random access unit.

According to a ninth aspect, a communications system is provided,including user equipment and at least one serving base station of theuser equipment, where multiple cell groups are configured for the userequipment, and a first serving base station in the at least one servingbase station of the user equipment is associated with at least two cellgroups of the multiple cell groups.

In a first possible implementation, the multiple cell groups include afirst SCG and a second cell group, where the second cell group is a MCGor a SCG, and the first SCG and the second cell group meet at least onetype of the following configuration transmitting uplink controlinformation related to a cell in the first SCG by using a PUCCH of afirst cell, where the first cell belongs to the second cell group of theuser equipment, processing data transmission on at least one cell in thefirst SCG by using a layer 2 functional entity located in the secondcell group, processing data transmission on at least one cell in thefirst SCG by using a security configuration parameter of the second cellgroup of the user equipment, or processing data transmission on at leastone cell in the first SCG by using a timing advance value of the secondcell group of the user equipment.

With reference to the foregoing possible implementation, in a secondpossible implementation, the first SCG and the second cell group areassociated with a same serving base station of the user equipment

With reference to the foregoing possible implementations, in a thirdpossible implementation, the at least one serving base station of theuser equipment is specifically one serving base station of the userequipment, and the multiple cell groups of the user equipment are allassociated with the one serving base station of the user equipment.

With reference to the foregoing possible implementations, in a fourthpossible implementation, the at least one serving base station of theuser equipment includes a MeNB and at least one SeNB, where the MeNB isassociated with a MCG of the multiple cell groups, and each of the atleast one SeNB is associated with one or more SCGs of the multiple cellgroups.

With reference to the foregoing possible implementation, in a fifthpossible implementation, the MeNB is further associated with one or moreSCGs of the multiple cell groups.

According to a tenth aspect, another network device is provided,including a processor configured to determine to allocate a first SCG touser equipment, and a transmitter configured to send first configurationindication information to the user equipment, where the firstconfiguration indication information is used to indicate at least onetype of the following configuration transmitting uplink controlinformation related to a cell in the first SCG by using a PUCCH of afirst cell, where the first cell belongs to a second SCG of the userequipment, or processing data transmission on at least one cell in thefirst SCG by using a layer 2 functional entity located in the secondSCG.

According to an eleventh aspect, another network device is provided,including a processor configured to determine to allocate a first cellgroup to user equipment, where the first cell group is a SCG, and atransmitter configured to send first configuration indicationinformation to the user equipment, where the first configurationindication information is used to indicate at least one type of thefollowing configuration, in a data transmission process in at least onecell in the first cell group, generating an encryption key by using asecurity configuration parameter of a second cell group of the userequipment, or in a data transmission process in at least one cell in thefirst cell group, performing uplink timing adjustment by using a timingadvance value of a second cell group of the user equipment.

According to a twelfth aspect, another user equipment is provided,including a receiver configured to receive first configurationindication information sent by a network device, where the firstconfiguration indication information is used to indicate at least onetype of the following configuration transmitting uplink controlinformation related to a cell in a first SCG of the user equipment byusing a PUCCH of a first cell, where the first cell belongs to a secondSCG of the user equipment, or processing data transmission on at leastone cell in a first SCG of the user equipment by using a layer 2functional entity located in the second SCG, and a processor configuredto configure the first SCG according to the first configurationindication information received by the receiver.

According to a thirteenth aspect, another user equipment is provided,including a receiver configured to receive first configurationindication information sent by a network device, where the firstconfiguration indication information is used to indicate at least onetype of the following configuration, in a data transmission process inat least one cell in a first cell group of the user equipment,generating an encryption key by using a security configuration parameterof a second cell group of the user equipment, or in a data transmissionprocess in at least one cell in the first cell group, performing uplinktiming adjustment by using a timing advance value of a second cell groupof the user equipment, and a processor configured to configure the firstcell group according to the first configuration indication informationreceived by the receiver.

Based on the foregoing technical solutions, in the communication methodprovided by the embodiments of the present disclosure, throughconfiguration, uplink control information related to a cell in a firstSCG of user equipment is transmitted by using a PUCCH of a first cell,where the first cell belongs to a second SCG of the user equipment,and/or data transmission on at least one cell in the first SCG isprocessed by using a layer 2 functional entity located in the secondSCG, so that a quantity of parameters maintained by the user equipmentcan be reduced, thereby reducing complexity of the user equipment.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of the presentdisclosure more clearly, the following briefly describes theaccompanying drawings required for describing the embodiments of thepresent disclosure or the prior art. Apparently, the accompanyingdrawings in the following description show merely some embodiments ofthe present disclosure, and persons of ordinary skill in the art maystill derive other drawings from these accompanying drawings withoutcreative efforts.

FIG. 1 is a schematic diagram of a DC scenario in the prior art,

FIG. 2 is a schematic flowchart of a communication method according toan embodiment of the present disclosure.

FIG. 3 is a schematic diagram of an example of an application scenarioaccording to an embodiment of the present disclosure.

FIG. 4 is a schematic diagram of another example of an applicationscenario according to an embodiment of the present disclosure.

FIG. 5 is a schematic diagram of another example of an applicationscenario according to an embodiment of the present disclosure.

FIG. 6 is a schematic flowchart of a communication method according toanother embodiment of the present disclosure.

FIG. 7 is a schematic flowchart of a communication method according toanother embodiment of the present disclosure.

FIG. 8 is a schematic flowchart of a communication method according toanother embodiment of the present disclosure.

FIG. 9 is a schematic flowchart of a communication method according toanother embodiment of the present disclosure.

FIG. 10 is a schematic flowchart of a communication method according toanother embodiment of the present disclosure.

FIG. 11 is a schematic flowchart of a communication method according toanother embodiment of the present disclosure.

FIG. 12 is a schematic flowchart of a communication method according toanother embodiment of the present disclosure.

FIG. 13 is a schematic flowchart of a communication method according toanother embodiment of the present disclosure.

FIG. 14 is a schematic flowchart of a communication method according toanother embodiment of the present disclosure.

FIG. 15 is a schematic block diagram of a network device according to anembodiment of the present disclosure.

FIG. 16 is a schematic block diagram of a network device according toanother embodiment of the present disclosure.

FIG. 17 is a schematic block diagram of user equipment according to anembodiment of the present disclosure.

FIG. 18 is a schematic block diagram of user equipment according toanother embodiment of the present disclosure.

FIG. 19 is a schematic block diagram of a network device according toanother embodiment of the present disclosure.

FIG. 20 is a schematic block diagram of a network device according toanother embodiment of the present disclosure.

FIG. 21 is a schematic block diagram of user equipment according toanother embodiment of the present disclosure.

FIG. 22 is a schematic block diagram of user equipment according toanother embodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present disclosure with reference to the accompanyingdrawings in the embodiments of the present disclosure. Apparently, thedescribed embodiments are merely a part rather than all of theembodiments of the present disclosure. All other embodiments obtained bya person of ordinary skill in the art based on the embodiments of thepresent disclosure without creative efforts shall fall within theprotection scope of the present disclosure.

It should be understood that, the technical solutions of the embodimentsof the present disclosure may be applied to various communicationssystems, such as a Global System for Mobile Communications (GSM) system,a Code Division Multiple Access (CDMA) system, a Wideband Code DivisionMultiple Access (WCDMA) system, a general packet radio service (GPRS), aLTE system, an LTE frequency division duplex (FDD) system, an LTE timedivision duplex (TDD) system, a Universal Mobile TelecommunicationsSystem (UMTS), and a Worldwide Interoperability for Microwave Access(WiMAX) communications system.

It should also be understood that in the embodiments of the presentdisclosure, user equipment (UE) may be referred to as a terminal, amobile station (MS), a mobile terminal, and the like. The user equipmentmay communicate with one or more core networks through a radio accessnetwork (RAN). For example, the user equipment may be a mobile phone(also referred to as a cellular phone) or a computer with a mobileterminal. For example, the user equipment may also be a portable,pocket-sized, handheld, computer built-in, or in-vehicle mobileapparatus, which exchanges voice and/or data with the radio accessnetwork.

It should also be understood that in the embodiments of the presentdisclosure, a base station may be a base transceiver station (BTS) inGSM or CDMA, or may be a NodeB in WCDMA, or may be an evolved NodeB(eNB, or e-NodeB) in LTE, which is not limited in the presentdisclosure.

It should also be understood that assuming that UE has only one servingbase station, a bearer in the embodiments of the present disclosure mayhave the following types.

Bearer type 1. A bearer that has a radio protocol stack (or an L2 entityor an L2 protocol stack) located in an MCG and an SCG and that usesresources of both the MCG and the SCG. The MCG and the SCG are bothassociated with the serving base station.

Bearer type 2. A bearer that has a radio protocol stack (or an L2 entityor an L2 protocol stack) located in a first SCG and a second SCG andthat uses resources of both the first SCG and the second SCG. The firstSCG and the second SCG are both associated with the serving basestation.

Assuming that UE has multiple serving base stations, a bearer in theembodiments of the present disclosure may further have the followingtypes.

Bearer type 3 (split bearer). A bearer that has a radio protocol stack(or an L2 entity or an L2 protocol stack) located in an MeNB (or an MCG)and an SeNB (or an SCG) and that uses only a resource of the SeNB (or aresource of the SCG).

Bearer type 4. A bearer that has a radio protocol stack (or an L2 entityor an L2 protocol stack) located in an MeNB and an SeNB and that usesresources of both the MeNB and the SeNB.

Bearer type 5. A bearer that has a radio protocol stack (or an L2 entityor an L2 protocol stack) located in a first SeNB (or a first SCG) and asecond SeNB (or a second SCG) and that uses only a resource of thesecond SeNB (or the second SCG).

Bearer type 6 (split bearer). A bearer that has a radio protocol stack(or an L2 entity or an L2 protocol stack) located in a first SeNB (or afirst SCG) and a second SeNB (or a second SCG) and that uses resourcesof both the first SeNB and the second SeNB.

FIG. 2 is a schematic flowchart of a communication method 100 accordingto an embodiment of the present disclosure. The method 100 may beperformed by a network side device such as a base station, a basestation controller, or a network side server. However, this embodimentof the present disclosure is not limited thereto. As shown in FIG. 2,the method 100 includes the following steps.

S110. Determine to allocate a first SCG to user equipment.

S120. Send first configuration indication information to the userequipment, where the first configuration indication information is usedto indicate at least one type of the following configurationtransmitting uplink control information related to a cell in the firstSCG by using a PUCCH of a first cell, where the first cell belongs to asecond SCG of the user equipment, or processing data transmission on atleast one cell in the first SCG by using a layer 2 functional entitylocated in the second SCG.

Therefore, according to the communication method in this embodiment ofthe present disclosure, through configuration, uplink controlinformation related to a cell in a first SCG of user equipment istransmitted by using a PUCCH of a first cell, where the first cellbelongs to a second SCG of the user equipment, and/or data transmissionon at least one cell in the first SCG is processed by using a layer 2functional entity located in the second SCG, so that a quantity ofparameters maintained by the user equipment can be reduced, therebyreducing complexity of the user equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

The network device may allocate the second SCG to the user equipmentbefore allocating the first SCG to the user equipment, and the secondSCG may have or have not been configured for the user equipment.Alternatively, the network device may allocate the second SCG to theuser equipment when allocating the first SCG to the user equipment. Inthis case, the first configuration indication information may be furtherused to indicate a configuration parameter of the second SCG that isdetermined by the network device. Data transmission on at least one cellin the second SCG may be processed by using a layer 2 functional entitylocated in the second SCG, and an independent PUCCH resource may havebeen configured for the second SCG. This is not limited in thisembodiment of the present disclosure.

Optionally, the transmitting uplink control information related to acell in the first SCG by using a PUCCH of a first cell includestransmitting an uplink control channel information related to a PSCellin the first SCG by using the PUCCH of the first cell, and transmittingan uplink control channel information related to a secondary cell in thefirst SCG by using the PUCCH of the first cell.

The first configuration indication information may be used to indicatetransmitting the uplink control information related to the cell in thefirst SCG on the PUCCH of the first cell. In this case, no independentPUCCH resource is configured for the first SCG. That is, no independentPUCCH resource is configured for the PSCell in the first SCG, and aPUCCH resource of the second SCG is shared by the first SCG and thesecond SCG. In addition, the data transmission on the at least one cellin the first SCG may be processed by a layer 2 functional entity locatedin the first SCG, and the user equipment needs to establish, in thefirst SCG, a layer 2 functional entity corresponding to the datatransmission on the at least one cell in the first SCG.

Alternatively, the first configuration indication information may beused to indicate processing the data transmission on the at least onecell in the first SCG by using the layer 2 functional entity located inthe second SCG. In this case, an independent PUCCH resource isconfigured for the first SCG. For example, a PUCCH resource isconfigured for a PSCell in the first SCG. The uplink control informationrelated to the cell in the first SCG may be transmitted by using thePUCCH configured for the first SCG. In addition, the data transmissionon the at least one cell in the first SCG may be processed by the layer2 functional entity located in the second SCG. The layer 2 functionalentity located in the second SCG may have been established or may benewly established by the user equipment for the data transmission. Theuser equipment does not need to establish, in the first SCG, a layer 2functional entity corresponding to the data transmission on the at leastone cell in the first SCG. However, this embodiment of the presentdisclosure is not limited thereto.

Alternatively, the first configuration indication information may beused to indicate transmitting the uplink control information related tothe cell in the first SCG by using the PUCCH of the first cell andindicate processing the data transmission on the at least one cell inthe first SCG by using the layer 2 functional entity located in thesecond SCG. In this case, the first SCG and the second SCG share a PUCCHresource of the second SCG, and the user equipment does not need toestablish, in the first SCG, a layer 2 functional entity correspondingto the data transmission on the at least one cell in the first SCG.

The first cell may be a PSCell in the second SCG or a secondary cell inthe second SCG, and a PUCCH is configured for the first cell.Optionally, the first cell is the PSCell in the second SCG.

Optionally, the uplink control information includes at least one of thefollowing information ACK, NACK, or CSI. However, this embodiment of thepresent disclosure is not limited thereto.

Optionally, the layer 2 functional entity may include at least one of aMedia Access Control entity, a Radio Link Control entity, or a PacketData Convergence Protocol entity. However, this embodiment of thepresent disclosure is not limited thereto.

In this embodiment of the present disclosure, the first configurationindication information explicitly or implicitly indicates the foregoingconfiguration of the first SCG. In an optional embodiment, the firstconfiguration indication information may include at least one of thefollowing information identification information of the second SCG oridentification information of the first cell, to implicitly indicate theforegoing configuration of the first SCG. For example, the foregoinginformation may be carried in a particular field of a configurationmessage. Correspondingly, when receiving the configuration message, theuser equipment may, according to the foregoing information carried inthe particular field, transmit the uplink control information related tothe cell in the first SCG by using the PUCCH of the first cell, and/orprocess the data transmission on the at least one cell in the first SCGby using the layer 2 functional entity located in the second SCG.However, this embodiment of the present disclosure is not limitedthereto.

In this embodiment of the present disclosure, the user equipment mayhave one or more serving base stations, and a MCG and multiple SCGs areconfigured for the user equipment. In an optional embodiment, thenetwork device may also determine a serving base station of the userequipment, with which the first SCG is associated. If the user equipmenthas multiple serving base stations, the first SCG may be associated witha MeNB of the multiple serving base stations or associated with a SeNBof the multiple serving base stations. This is not limited in thisembodiment of the present disclosure. Correspondingly, the firstconfiguration indication information may be further used to indicate abase station associated with the first SCG.

In an optional embodiment, all cell groups configured for the userequipment are associated with a same serving base station of the userequipment.

In this case, zero or at least one cell group that has been configuredfor the user equipment and at least one cell group newly allocated bythe network device to the user equipment may be associated with a sameserving base station. The serving base station may be a unique servingbase station of the user equipment or a MeNB in multiple serving basestations of the user equipment. This embodiment of the presentdisclosure is not limited thereto. For example, as shown in FIG. 3, theMCG, the first SCG, and the second SCG of the user equipment are allassociated with the unique serving base station of the user equipment.

In another optional embodiment, the user equipment has multiple servingbase stations, and the first SCG and the second SCG are associated withdifferent base stations.

As shown in FIG. 4 and FIG. 5, the multiple serving base stations of theuser equipment may include a MeNB and at least one SeNB. There is an RRCconnection between the user equipment and the MeNB. There is a commonradio connection between the user equipment and each of the at least oneSeNB. In addition, there may be a non-ideal backhaul (non-idealbackhaul) link between the MeNB and the at least one SeNB, and the MeNBcommunicates with the at least one SeNB by using an X2 interface. Inthis case, the MeNB of the user equipment may be associated with the MCGand zero or at least one SCG of the user equipment. Each of the at leastone SeNB may be associated with zero or at least one SCG. However, thisembodiment of the present disclosure is not limited thereto.

If the multiple serving base stations of the user equipment include aMeNB and at least one SeNB, the first SCG and the second SCG may beassociated with a same base station or different base stations. In anembodiment, the first SCG may be associated with the MeNB, and thesecond SCG is associated with the MeNB or the SeNB. Alternatively, thefirst SCG and the second SCG may be both associated with a same SeNB ofthe at least one SeNB. Alternatively, the first SCG may be associatedwith a first SeNB of the at least one SeNB, and the second SCG isassociated with the MeNB or a second SeNB, different from the firstSeNB, included in the at least one SeNB. This embodiment of the presentdisclosure is not limited thereto.

In another optional embodiment, if the serving base station associatedwith the first SCG controls multiple cells, the network device may alsodetermine at least one cell included in the first SCG. The first SCG mayinclude some or all cells controlled by the associated serving basestation. In addition, if the first SCG includes multiple cells, thenetwork device may also determine which of the multiple cells serves asthe PSCell in the first SCG. Correspondingly, the first configurationindication information may be further used to indicate at least one cellincluded in the first SCG, or be further used to indicate a PSCell in atleast one cell included in the first SCG. However, this embodiment ofthe present disclosure is not limited thereto.

In an optional embodiment, the first configuration indicationinformation may be used to indicate whether the first SCG has anindependent PUCCH resource. If the first SCG does not have anindependent PUCCH resource, the first configuration indicationinformation is used to instruct the first SCG and the second SCG toshare a PUCCH configured for the second SCG. That is, the uplink controlinformation related to the cell in the first SCG is transmitted by usingthe PUCCH of the first cell. In this case, none of the cells included inthe first SCG has an independent PUCCH resource. The PSCell in the firstSCG does not have an independent PUCCH resource either, but the PSCellin the first SCG may serve as a downlink timing reference cell in thefirst SCG. This is not limited in this embodiment of the presentdisclosure.

In another optional embodiment, the first configuration indicationinformation may be used to indicate whether to establish, in the firstSCG, a layer 2 functional entity configured to process the datatransmission on the at least one cell in the first SCG. If a layer 2functional entity configured to process the data transmission on the atleast one cell in the first SCG does not need to be established in firstSCG, the first configuration indication information may indicateprocessing the data transmission on the at least one cell in the firstSCG by using the layer 2 functional entity located in the second SCG.The layer 2 functional entity may include at least one of the followinga Media Access Control (MAC) entity, a Radio Link Control (RLC) entity,or a Packet Data Convergence Protocol (PDCP) entity. The MAC entity maybe established when the user equipment initially configures the firstSCG, and the RLC entity and the PDCP entity may be established when abearer of the first SCG is created.

Optionally, the first configuration indication information may includeidentification information of the second SCG and/or identificationinformation of a PSCell in the second SCG, to implicitly indicateprocessing the data transmission on the at least one cell in the firstSCG by using the layer 2 functional entity located in the second SCG.The first configuration indication information may indicate togetherwhether a MAC entity, an RLC entity, and a PDCP entity that areconfigured to process the data transmission on the at least one cell inthe first SCG need to be established in the first SCG. Alternatively,the first configuration indication information may separately indicatewhether each of the foregoing entities configured to process the datatransmission on the at least one cell in the first SCG needs to beestablished in the first SCG. However, this embodiment of the presentdisclosure is not limited thereto.

In an optional embodiment, the first configuration indicationinformation may be used to indicate processing the data transmission onthe at least one cell in the first SCG by using an RLC entity and a PDCPentity that are located in the second SCG, while a MAC entity configuredto process the data transmission on the at least one cell in the firstSCG may be located in the first SCG. However, this embodiment of thepresent disclosure is not limited thereto.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing, in the second SCG,at least one of a PDCP entity or an RLC entity that corresponds to abearer of the first SCG.

The processing data transmission on at least one cell in the first SCGby using a layer 2 functional entity located in the second SCG of theuser equipment includes processing data transmission on the bearer ofthe first SCG by using at least one of the PDCP entity or the RLC entitythat is established in the second SCG and that corresponds to thebearer.

In an embodiment, the first configuration indication information may beused to indicate establishing, in the second SCG, the PDCP entitycorresponding to the bearer of the first SCG, and processing the datatransmission on the bearer by using the PDCP entity that is establishedin the second SCG and that corresponds to the bearer. Alternatively, thefirst configuration indication information may be used to indicateestablishing, in the second SCG, the PDCP entity and the RLC entity thatcorrespond to the bearer of the first SCG, and processing the datatransmission on the bearer by using the PDCP entity and the RLC entitythat are established in the second SCG and that correspond to thebearer. However, this embodiment of the present disclosure is notlimited thereto.

In this embodiment of the present disclosure, the bearer of the firstSCG may be a bearer that uses a resource of the first SCG. Optionally,the bearer of the first SCG may use only a resource of the first SCG. Inthis case, a layer 2 functional entity of the bearer of the first SCGmay be located in the first SCG or the second SCG. However, thisembodiment of the present disclosure is not limited thereto.

Optionally, if the second SCG has been configured, the bearer of thefirst SCG may have been established in the second secondary cell. Afterthe first SCG is configured, transmission of the bearer may be performedin both the second secondary cell and the first SCG. Alternatively, thebearer of the first SCG may be established after the first SCG isconfigured. This embodiment of the present disclosure is not limitedthereto.

Alternatively, the bearer of the first SCG may use resources of thefirst SCG and another cell group (which may be a MCG or a SCG). Theanother cell group and the first SCG may be associated with a same basestation. In this case, a layer 2 functional entity of the bearer of thefirst SCG may be located in the first SCG and the another cell group orlocated in the second SCG and the another cell group. However, thisembodiment of the present disclosure is not limited thereto.

Alternatively, the bearer of the first SCG may use resources of thefirst SCG and another cell group (which may be a MCG or a SCG). Theanother SCG and the first SCG may be associated with different basestations. In this case, the bearer of the first SCG is a split bearer,and a layer 2 functional entity of the split bearer may be located inthe first SCG and the another cell group or located in the second SCGand the another cell group. However, this embodiment of the presentdisclosure is not limited thereto.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing a split bearer ofthe first SCG and the second SCG and indicate a SCG, used to perform asplit operation, in the first SCG and the second SCG.

In the split bearer, a part of a data packet is transmitted by using thefirst SCG, and the other part is transmitted by using the second SCG.That is, the split bearer uses resources of the first SCG and the secondSCG. In this case, a layer 2 functional entity of the split bearer maybe located only in the first SCG, be located only in the second SCG, orbe located in the first SCG and the second SCG. This embodiment of thepresent disclosure is not limited thereto. Further, the firstconfiguration indication information may indicate a cell group, whichperforms the split operation, in the first SCG and the second SCG. Thatis, the data packet is split into two parts that are respectivelytransmitted by using the first SCG and the second SCG. However, thisembodiment of the present disclosure is not limited thereto.

Alternatively, the first configuration indication information is furtherused to instruct the first SCG and the second SCG to establish a splitbearer and indicate a SCG corresponding to a layer 2 functional entitythat performs a split operation of the split bearer or indicate a SCG,in which the layer 2 functional entity (or a Radio Link Protocol entity)of the split bearer is located, of the first SCG and the second SCG. Inan embodiment, if the split bearer is split at a PDCP layer, the firstconfiguration indication information may indicate an SCG correspondingto the PDCP layer at which the bearer is split, that is, an SCG,corresponding to the PDCP layer at which the split operation isperformed, of a first SCG and a second SCG, or indicate a SCG, in whicha PDCP entity of the split bearer is located, of the first SCG and thesecond SCG. The PDCP entity of the split bearer may be located in atleast one SCG of the first SCG and the second SCG. Alternatively, if thesplit bearer is split at an RLC layer, the SCG configuration informationmay indicate an SCG corresponding to the RLC layer at which the beareris split, that is, an SCG, corresponding to the RLC layer at which thesplit operation is performed, of a first SCG and a second SCG, orindicate a SCG, in which an RLC entity of the split bearer is located,of the first SCG and the second SCG. The RLC entity of the split bearermay be located in at least one SCG of the first SCG and the second SCG.However, this embodiment of the present disclosure is not limitedthereto.

After receiving the first configuration indication information, the userequipment may establish a correspondence between the first SCG and thesecond SCG, configure the first SCG according to the first configurationindication information, and send a configuration complete message to thenetwork device after completing configuring the first SCG.

In another optional embodiment, the method 100 further includesreceiving a configuration complete message that is sent by the userequipment according to the first configuration indication information.

In another optional embodiment, if the network device is a MeNB of theuser equipment, and the first SCG is associated with the first SeNB ofthe user equipment, before S120, the method 100 further includes sendingsecond configuration indication information to the first SeNB, where thesecond configuration indication information is used to indicate aconfiguration parameter of the first SCG that is determined by thenetwork device, and the configuration parameter includes at least one ofa PUCCH of the first SCG or a layer 2 functional entity corresponding tothe data transmission on the at least one cell in the first SCG, andreceiving a configuration response message that is sent by the firstSeNB according to the second configuration indication information.

Correspondingly, S120 of sending first configuration indicationinformation to the user equipment includes sending the firstconfiguration indication information to the user equipment according tothe configuration response message.

In this embodiment of the present disclosure, the configurationparameter of the first SCG may be independently determined by the MeNB,and the MeNB notifies the first SeNB of the configuration parameter ofthe first SCG. In this case, the second configuration indicationinformation may be used to notify the first SeNB of the configurationparameter determined by the network device. After receiving the secondconfiguration indication information, the first SeNB may determine theconfiguration parameter of the first SeNB that is indicated in thesecond configuration indication information and send a configurationresponse message to the MeNB, to determine that the first SeNB hasreceived the second configuration indication information.

Alternatively, a configuration parameter of the first SCG may bedetermined by the MeNB and the first SeNB by means of negotiation. Inthis case, the second configuration indication information may be usedto indicate the configuration parameter of the first SCG that isdetermined by the first SeNB. After receiving the second configurationindication information, the first SeNB may agree upon the configurationparameter determined by the MeNB, or modify the configuration parameterdetermined by the MeNB, add the configuration parameter determined bythe first SeNB into the configuration response message and send theconfiguration response message to the MeNB. In the configurationparameter of the first SCG that is determined by the first SeNB, theuplink control information related to the cell in the first SCG istransmitted by using the PUCCH of the first cell, and/or the datatransmission on the at least one cell in the first SCG is processed byusing the layer 2 functional entity located in the second SCG. The MeNBmay obtain the configuration parameter of the first SCG that isdetermined by the first SeNB and that is carried in the configurationresponse message, determine, according to the configuration responsemessage, that the uplink control information related to the cell in thefirst SCG is transmitted by using the PUCCH of the first cell, and/orthe data transmission on the at least one cell in the first SCG isprocessed by the layer 2 functional entity located in the second SCG,and send the configuration parameter of the first secondary cell that isdetermined according to the configuration response message to the userequipment. However, this embodiment of the present disclosure is notlimited thereto.

In another optional embodiment, the configuration response messagecarries a configuration parameter of the first SCG that is determined bythe first SeNB according to the second configuration indicationinformation, and the configuration response message indicates at leastone type of the following configuration transmitting the uplink controlinformation of the cell in the first SCG by using the PUCCH of the firstcell, or processing the data transmission on the at least one cell inthe first SCG by using the layer 2 functional entity located in thesecond SCG. The configuration parameter of the first SCG that isdetermined by the first SeNB may be different from the configurationparameter of the first SCG that is determined by the MeNB.Correspondingly, the sending the first configuration indicationinformation to the user equipment according to the configurationresponse message includes determining at least one type of the followingconfiguration according to the second configuration indicationinformation transmitting the uplink control information of the cell inthe first SCG by using the PUCCH of the first cell, or processing thedata transmission on the at least one cell in the first SCG by using thelayer 2 functional entity located in the second SCG.

In another optional embodiment, the first configuration indicationinformation is further used to indicate at least one type of thefollowing configuration. in a data transmission process in at least onecell in a first cell group, generating an encryption key by using asecurity configuration parameter of a second cell group of the userequipment, or in a data transmission process in at least one cell in thefirst cell group, performing uplink timing adjustment by using a timingadvance value of a second cell group of the user equipment.

The first SCG and the second SCG may share a security configurationparameter and/or a timing advance value. In this case, the first SCG andthe second SCG may be associated with a same serving base station of theuser equipment. However, this embodiment of the present disclosure isnot limited thereto. Optionally, the first SCG and the second SCG mayuse a same security configuration parameter. The security configurationparameter may be allocated by a network side to the first SCG, and inthis case, the network side does not allocate an independent securityconfiguration parameter to the second SCG. Alternatively, the securityconfiguration parameter may be allocated by a network side to the secondSCG, and in this case, the network side does not allocate an independentsecurity configuration parameter to the first SCG. Alternatively, thesecurity configuration parameter may be allocated by a network side toanother cell group of the user equipment, the network side does notallocate an independent security configuration parameter to the firstSCG and the second SCG, and the another cell group, the first SCG, andthe second SCG may be associated with a same serving base station.However, this embodiment of the present disclosure is not limitedthereto.

In an optional embodiment, the first configuration indicationinformation is used to instruct the first SCG to generate an encryptionkey by using a security configuration parameter of the second SCG.

The security configuration parameter may include at least one of thefollowing parameters a SCG counter, a SCG intermediate key (or SecondaryeNB intermediate key, S-KeNB), an index value of a SCG intermediate key,or a serial number of a SCG intermediate key. The SCG intermediate keymay be determined according to a MeNB intermediate key (KeNB) and asecondary cell counter. In this case, the first configuration indicationinformation may include identification information of the second SCG orinclude at least one of the following information a SCG intermediate keyof the second SCG, an index value of a SCG intermediate key of thesecond SCG, a serial number of a SCG intermediate key of the second SCG,or an SCG counter (counter) of the second SCG. In addition, the firstconfiguration indication information may further instruct the first SCGand the second SCG to use a same encryption algorithm. However, thisembodiment of the present disclosure is not limited thereto.

Optionally, because the PDCP entity has a function of managing a SCGintermediate key, the first configuration indication information mayimplicitly indicate, by indicating processing the data transmission onthe at least one cell in the first cell group by using a PDCP entitylocated in the second cell group, that in the data transmission processin the at least one cell in the first cell group, the encryption key isgenerated by using the security configuration parameter of the secondcell group of the user equipment. However, this embodiment of thepresent disclosure is not limited thereto.

After receiving the first configuration indication information, the userequipment may determine, according to the first configuration indicationinformation, a SCG intermediate key used by the first SCG, obtain anencryption key according to the SCG intermediate key and an encryptionalgorithm, and use the encryption key to encrypt to-be-transmitted data.

In another optional embodiment, the first configuration indicationinformation may be further used to instruct the first SCG and the secondSCG to use a same timing advance value. That is, in a data transmissionprocess in the at least one cell in the first SCG, uplink timingadjustment is performed by using a timing advance value of the secondSCG. In this case, the user equipment may perform uplink timingadjustment on the first SCG by using the timing advance value of thesecond SCG. The first configuration indication information may includeinformation about a timing advance value of the second SCG or includeinformation about a TAG to which the first SCG belongs. The first SCGand the second SCG belong to a same TAG, implicitly indicating that thefirst SCG and the second SCG use a same timing advance value. In thiscase, the network device may configure a random access resource only forone SCG of the second SCG and the first SCG, for example, configure arandom access resource only for the second SCG. The user equipment mayperform a random access procedure in the second SCG by using the randomaccess resource configured by the network device, and obtain a timingadvance value of the second SCG. Because the first SCG and the secondSCG have a same TA value, the user equipment directly performs uplinktiming adjustment in the data transmission process in the at least onecell in the first SCG by using the timing advance value of the secondSCG, without performing a random access procedure in the first SCG.However, this embodiment of the present disclosure is not limitedthereto.

Alternatively, the network side may configure random access resourcesfor both the first SCG and the second SCG. In this case, whendetermining that the first SCG and the second SCG belong to a same TAG,the user equipment may perform a random access procedure only in thefirst SCG or the second SCG, instead of in both cell groups, to obtain atiming advance (TA) value corresponding to the TAG, thereby reducingsystem resources and reducing UE power consumption.

Therefore, according to the communication method in this embodiment ofthe present disclosure, through configuration, uplink controlinformation related to a cell in a first SCG of user equipment istransmitted by using a PUCCH of a first cell, where the first cellbelongs to a second SCG of the user equipment, and/or data transmissionon at least one cell in the first SCG is processed by using a layer 2functional entity located in the second SCG, so that a quantity ofparameters maintained by the user equipment can be reduced, therebyreducing complexity of the user equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

FIG. 6 shows another communication method 200 provided by an embodimentof the present disclosure. The method 200 may be performed by a networkside device such as a base station, a base station controller, or anetwork side server. However, this embodiment of the present disclosureis not limited thereto. As shown in FIG. 6, the method 200 includes thefollowing steps.

S210. Determine to allocate a first cell group to user equipment, wherethe first cell group is a SCG.

S220. Send first configuration indication information to the userequipment, where the first configuration indication information is usedto indicate at least one type of the following configuration, in a datatransmission process in at least one cell in the first cell group,generating an encryption key by using a security configuration parameterof a second cell group of the user equipment, or in a data transmissionprocess in at least one cell in the first cell group, performing uplinktiming adjustment by using a timing advance value of a second cell groupof the user equipment.

Therefore, according to the communication method in this embodiment ofthe present disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

The network device may allocate the second SCG to the user equipmentbefore allocating the first SCG to the user equipment. Alternatively,the network device may allocate the second SCG to the user equipmentwhen allocating the first SCG to the user equipment. In this case, thefirst configuration indication information may be further used toindicate a configuration parameter of the second SCG that is determinedby the network device. However, this embodiment of the presentdisclosure is not limited thereto.

The first configuration indication information may be used to indicatethat the first cell group uses the security configuration parameter ofthe second cell group to generate the encryption key. In this case, theuser equipment may perform random access procedures respectively in thefirst cell group and the second cell group, to obtain timing advancevalues respectively corresponding to the first cell group and the secondcell group.

Alternatively, the first configuration indication information may beused to indicate that in the data transmission process in the at leastone cell in the first cell group, uplink timing adjustment is performedby using the timing advance value of the second cell group of the userequipment. In this case, the first cell group and the second cell groupshare a timing advance value that is obtained by the user equipment byperforming a random access procedure in the second cell group. That is,the user equipment does not need to perform a random access procedure inthe first cell group. In addition, the first cell group and the secondcell group may use different security configuration parameters togenerate encryption keys.

Alternatively, the first configuration indication information may beused to indicate that in the data transmission process in the at leastone cell in the first cell group, the encryption key is generated byusing the security configuration parameter of the second cell group ofthe user equipment, and in the data transmission process in the at leastone cell in the first cell group, uplink timing adjustment is performedby using the timing advance value of the second cell group of the userequipment. In this case, the first cell group and the second cell groupshare a security configuration parameter allocated by a network side tothe second cell group, and the first cell group and the second cellgroup share a timing advance value that is obtained by the userequipment by performing a random access procedure in the second cellgroup. That is, the user equipment does not need to perform a randomaccess procedure in the first cell group.

Optionally, the security configuration parameter may include at leastone of the following parameters a SCG counter, a SCG intermediate key,an index value of a SCG intermediate key, or a serial number of a SCGintermediate key. Optionally, the first configuration indicationinformation may be further used to indicate an encryption algorithm thatis used when the first SCG generates the encryption key. For example,the first configuration indication information may be further used toindicate that the first cell group generates an encryption key by usingan encryption algorithm of the second cell group. However, thisembodiment of the present disclosure is not limited thereto.

The first cell group is a SCG, and the second cell group may be a MCG ora SCG different from the first cell group. However, this embodiment ofthe present disclosure is not limited thereto.

Optionally, the first cell group and the second cell group areassociated with a same serving base station of the user equipment.

The user equipment may have one or more serving base stations. If theuser equipment has only one serving base station, all cell groups of theuser equipment are associated with the serving base station of the userequipment. If the user equipment has multiple serving base stations, andthe multiple serving base stations include a MeNB and at least one SeNB,both the first cell group and the second cell group may be associatedwith the MeNB of the user equipment or associated with one SeNB of theuser equipment. This is not limited in this embodiment of the presentdisclosure.

In an optional embodiment, the multiple serving base stations of theuser equipment include a MeNB and at least one SeNB. The second cellgroup is a SCG, and the first cell group and the second cell group areboth associated with a same SeNB of the user equipment.

In this case, the network device may be a SeNB associated with the firstcell group and the second cell group, or may be a MeNB of the userequipment. This is not limited in this embodiment of the presentdisclosure.

The first configuration indication information may be further used toindicate a base station associated with the first SCG, at least one cellincluded in the first SCG, or a PSCell of the at least one cell includedin the first SCG. This embodiment of the present disclosure is notlimited thereto.

The first configuration indication information may explicitly orimplicitly indicate the foregoing configuration. For example, the firstconfiguration indication information may include identificationinformation of the second SCG and/or identification information of aPSCell in the second SCG, to implicitly indicate that in the datatransmission process in the at least one cell in the first cell group,the encryption key is generated by using the security configurationparameter of the second cell group of the user equipment, and/or in thedata transmission process in the at least one cell in the first cellgroup, uplink timing adjustment is performed by using the timing advancevalue of the second cell group of the user equipment. However, thisembodiment of the present disclosure is not limited thereto.

For another example, because a PDCP entity is responsible for managingthe security configuration parameter, the first configuration indicationinformation may implicitly indicate, by indicating that the datatransmission on the at least one cell in the first cell group isperformed by using a PDCP entity located in the second cell group, thatthe first cell group uses the security configuration parameter of thesecond cell group.

For another example, by indicating that the first cell group and thesecond cell group belong to a same TAG, or indicating that a PSCell inthe first cell group and a PSCell or a PCell in the second cell groupbelong to a same TAG, the first configuration indication information mayimplicitly indicate that in the data transmission process in the atleast one cell in the first cell group, uplink timing adjustment isperformed by using the timing advance value of the second cell group ofthe user equipment. However, this embodiment of the present disclosureis not limited thereto.

If uplink timing adjustment is performed in the data transmissionprocess in the first cell group by using the TA value of the second cellgroup, the network device may not allocate a random access resource tothe first cell group, but allocates a random access resource only to thesecond cell group. Correspondingly, the user equipment may perform arandom access procedure in the second cell group by using the randomaccess resource, to obtain the TA value of the second cell group, andperform uplink timing adjustment in the data transmission process in theat least one cell in the first cell group by using the TA value, withoutperforming a random access procedure in the first cell group, therebyreducing system resources and reducing power consumption of the userequipment.

In another optional embodiment, the first configuration indicationinformation is further used to indicate that the first cell group doesnot have a random access resource. A random access resource isconfigured for the second cell group, and the timing advance value ofthe second cell group is obtained by the user equipment by performing arandom access procedure in the second cell group by using the randomaccess resource.

After receiving the first configuration indication information, the userequipment may determine, according to the first configuration indicationinformation, that in the data transmission process in the at least onecell in the first cell group, an encryption key is generated by usingthe security configuration parameter of the second cell group, and/or inthe data transmission process in the at least one cell in the first cellgroup, uplink timing adjustment is performed by using the timing advancevalue of the second cell group, establish a correspondence between thefirst cell group and the second cell group, and configure the first cellgroup according to the first configuration indication information. Inanother optional embodiment, the method 200 further includes receiving aconfiguration complete message that is sent by the user equipmentaccording to the first configuration indication information.

In another embodiment, if the network device is a first SeNB associatedwith both the first cell group and the second cell group, and the userequipment has at least two serving base stations including a MeNB andthe first SeNB, before 5210, the method 200 further includes receivingsecond configuration indication information sent by the MeNB, where thesecond configuration indication information is used to instruct thefirst SeNB to allocate the first cell group to the user equipment.

Correspondingly, S210 of determining to allocate a first cell group touser equipment includes determining, according to the secondconfiguration indication information, to allocate the first cell groupto the user equipment.

The MeNB of the user equipment may instruct the first SeNB to allocatethe first cell group to the user equipment. Correspondingly, the firstSeNB may allocate the first cell group to the user equipment accordingto an instruction of the MeNB and determine a configuration parameter ofthe first cell group. Alternatively, the first SeNB may proactivelydetermine to configure the first cell group associated with the firstSeNB for the user equipment. However, this embodiment of the presentdisclosure is not limited thereto.

In another optional embodiment, the first configuration indicationinformation may be further used to indicate at least one type of thefollowing configuration transmitting uplink control information relatedto a cell in the first SCG by using a PUCCH of a first cell, where thefirst cell belongs to a second SCG of the user equipment, or processingdata transmission on at least one cell in the first SCG by using a layer2 functional entity located in the second SCG.

Therefore, according to the communication method in this embodiment ofthe present disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

With reference to FIG. 2 to FIG. 6, the communication methods providedby the embodiments of the present disclosure are described in detailabove from a perspective of a network device. With reference to FIG. 7and FIG. 8, communication methods provided by embodiments of the presentdisclosure are described in detail below from a perspective of userequipment.

FIG. 7 shows a communication method 300 provided by an embodiment of thepresent disclosure. The method may be performed by user equipment. Asshown in FIG. 7, the method 300 includes the following steps.

S310. Receive first configuration indication information sent by anetwork device, where the first configuration indication information isused to indicate at least one type of the following configurationtransmitting uplink control information related to a cell in a first SCGof the user equipment by using a PUCCH of a first cell, where the firstcell belongs to a second SCG of the user equipment, or processing datatransmission on at least one cell in a first SCG of the user equipmentby using a layer 2 functional entity located in the second SCG.

S320. Configure the first SCG according to the first configurationindication information.

Therefore, according to the communication method in this embodiment ofthe present disclosure, through configuration, uplink controlinformation related to a cell in a first SCG of user equipment istransmitted by using a PUCCH of a first cell, where the first cellbelongs to a second SCG of the user equipment, and/or data transmissionon at least one cell in the first SCG is processed by using a layer 2functional entity located in the second SCG, so that a quantity ofparameters maintained by the user equipment can be reduced, therebyreducing complexity of the user equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

The first SCG and the second SCG may be associated with a same servingbase station of the user equipment, or the first SCG and the second SCGmay be associated with different serving base stations of the userequipment. For example, the first SCG is associated with a SeNB of theuser equipment, and the second SCG is associated with a MeNB or anotherSeNB of the user equipment. This is not limited in embodiments of thepresent disclosure.

The first configuration indication information may be carried in aconfiguration message, and the configuration message may carry aconfiguration parameter of the first SCG that is determined by thenetwork device. However, this embodiment of the present disclosure isnot limited thereto.

In an optional embodiment, the first cell is a PSCell in the second SCGof the user equipment.

Optionally, the uplink control information includes at least one of thefollowing information acknowledgment information ACK, negativeacknowledgment information NACK, or CSI.

In another optional embodiment, a PUCCH is configured for the PSCell inthe second SCG. In this case, the first configuration indicationinformation is used to indicate transmitting an uplink control channelrelated to at least one cell in the first SCG by using the PUCCHconfigured for the PSCell in the second SCG.

In another optional embodiment, the first configuration indicationinformation includes at least one of the following informationidentification information of the second SCG or identificationinformation of the first cell.

If the first cell is not the PSCell in the second SCG, the firstconfiguration indication information includes at least one of thefollowing information identification information of the second SCG,identification information of the first cell, or identificationinformation of a PSCell in the second SCG.

In this case, the configuring, by the user equipment, the first SCGaccording to the first configuration indication information includesdetermining at least one type of the following configuration accordingto at least one of the identification information of the second SCG ofthe user equipment or the identification information of the first celltransmitting the uplink control information related to the cell in thefirst SCG of the user equipment by using the PUCCH of the first cell,where the first cell belongs to the second SCG of the user equipment, orprocessing the data transmission on the at least one cell in the firstSCG of the user equipment by using the layer 2 functional entity locatedin the second SCG.

In an embodiment, a particular field in the configuration message maycarry the identification information of the second SCG, to indicate atleast one type of the foregoing configuration. Alternatively, aparticular field in the configuration message may carry theidentification information of the PSCell in the second SCG, to indicateat least one type of the foregoing configuration. However, thisembodiment of the present disclosure is not limited thereto.

In another optional embodiment, the layer 2 functional entity includesat least one of a Media Access Control entity, a Radio Link Controlentity, or a Packet Data Convergence Protocol entity.

For example, the first configuration indication information may indicateprocessing the data transmission on the at least one cell in the firstSCG by using an RLC entity and a PDCP entity that are located in thesecond SCG, while a MAC entity configured to process the datatransmission on the at least one cell in the first SCG may be located inthe first SCG. However, this embodiment of the present disclosure is notlimited thereto.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing, in the second SCG,at least one of a Packet Data Convergence Protocol entity or a RadioLink Control entity that corresponds to a bearer of the first SCG.

Correspondingly, the processing data transmission on at least one cellin a first SCG by using a layer 2 functional entity established in thesecond SCG of the user equipment includes processing data transmissionon the bearer of the first SCG by using at least one of the Packet DataConvergence Protocol entity or the Radio Link Control entity that isestablished in the second SCG and that corresponds to the bearer.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing a split bearer ofthe first SCG and the second SCG and indicate a SCG, used to perform asplit operation, in the first SCG and the second SCG.

In another embodiment, the method 300 further includes sending aconfiguration complete message to the network device.

In another embodiment, the first configuration indication information isfurther used to indicate at least one type of the followingconfiguration, in a data transmission process in the at least one cellin the first SCG, generating an encryption key by using a securityconfiguration parameter of the second SCG of the user equipment, or in adata transmission process in the at least one cell in the first SCG,performing uplink timing adjustment by using a timing advance value ofthe second SCG of the user equipment.

Therefore, according to the communication method in this embodiment ofthe present disclosure, through configuration, uplink controlinformation related to a cell in a first SCG of user equipment istransmitted by using a PUCCH of a first cell, where the first cellbelongs to a second SCG of the user equipment, and/or data transmissionon at least one cell in the first SCG is processed by using a layer 2functional entity located in the second SCG, so that a quantity ofparameters maintained by the user equipment can be reduced, therebyreducing complexity of the user equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

FIG. 8 shows a communication method 400 provided by another embodimentof the present disclosure. The method 400 may be performed by userequipment. As shown in FIG. 8, the method 400 includes the followingsteps.

S410. Receive first configuration indication information sent by anetwork device, where the first configuration indication information isused to indicate at least one type of the following configuration, in adata transmission process in at least one cell in a first cell group ofthe user equipment, generating an encryption key by using a securityconfiguration parameter of a second cell group of the user equipment, orin a data transmission process in at least one cell in the first cellgroup, performing uplink timing adjustment by using a timing advancevalue of a second cell group of the user equipment.

S420. Configure the first cell group according to the firstconfiguration indication information.

Therefore, according to the communication method in this embodiment ofthe present disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

In an optional embodiment, the first cell group and the second cellgroup are associated with a same serving base station of the userequipment.

In another embodiment, the second cell group is a MCG or a SCG.

Specifically, if the second cell group is a MCG, the first cell groupand the second cell group may be both associated with a MeNB of the userequipment. If the second cell group is a SCG, the first cell group andthe second cell group may be both associated with a MeNB or a same SeNBof the user equipment. This is not limited in this embodiment of thepresent disclosure.

In another embodiment, the serving base station of the user equipmentincludes a MeNB and at least one SeNB. In this case, the second cellgroup is a SCG, and the first cell group and the second cell group areboth associated with the SeNB of the user equipment.

In another embodiment, the security configuration parameter includes atleast one of the following a SCG counter, a SCG intermediate key, anindex value of a SCG intermediate key, or a serial number of a SCGintermediate key.

In another optional embodiment, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, generating an encryption key byusing a security configuration parameter of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate processing data transmission on the at least onecell in the first cell group by using a Packet Data Convergence Protocolentity located in the second cell group.

In this case, S420 of configuring the first cell group according to thefirst configuration indication information includes according to thefirst configuration indication information, that is, the datatransmission on the at least one cell in the first cell group isprocessed by using the Packet Data Convergence Protocol entity locatedin the second cell group, which is indicated in, determining that in thedata transmission process in the at least one cell in the first cellgroup, an encryption key is generated by using a security configurationparameter of the second cell group of the user equipment.

In another optional embodiment, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate that the first cell group of the user equipment andthe second cell group of the user equipment belong to a same TAG, or thefirst configuration indication information is used to indicate that aPSCell in the first cell group of the user equipment and a PSCell or aPCell in the second cell group of the user equipment belong to a sameTAG.

In this case, S420 of configuring the first cell group according to thefirst configuration indication information includes according to thefirst configuration indication information, that is, the first cellgroup and the second cell group belong to the same TAG or the PSCell inthe first cell group and the PSCell or the PCell in the second cellgroup belong to the same TAG, determining that in the data transmissionprocess in the at least one cell in the first cell group, uplink timingadjustment is performed by using the timing advance value of the secondcell group of the user equipment.

In another embodiment, the method 400 further includes receiving secondconfiguration indication information sent by the network device, wherethe second configuration indication information is used to indicate arandom access resource allocated by the network device to the secondcell group, performing a random access process in the second cell groupaccording to the second configuration indication information, to obtaina timing advance value of the second cell group, and communicating withthe serving base station of the user equipment in the first cell groupaccording to the timing advance value of the second cell group.

In another embodiment, the method 400 further includes sending aconfiguration complete message to the network device.

Therefore, according to the communication method in this embodiment ofthe present disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

The communication method provided by this embodiment of the presentdisclosure is described in further detail below with reference tospecific examples.

FIG. 9 shows a communication method 500 provided by another embodimentof the present disclosure. For convenience of description, in thisembodiment, it is assumed that user equipment has a MeNB and at leastone SeNB, and a network device is the MeNB MeNB of the user equipment.However, this embodiment of the present disclosure is not limitedthereto.

S510. The MeNB determines that a first SCG needs to be added for the UE,and determines configuration information of the first SCG. Theconfiguration information includes configuration information of a firstPSCell and configuration information of a second PSCell. The firstPSCell is a PSCell of a newly configured first SCG, and no PUCCHresource is configured for the first PSCell. The second PSCell is aPSCell of a second SCG that has been configured or a PSCell of anothernewly added second SCG that is configured when the first SCG isconfigured, and a PUCCH resource is configured for the second PSCell.

S520. The MeNB sends an SCG configuration message to the UE, andconfigures a newly added SCG for the UE, where the SCG configurationmessage includes configuration information of the newly added SCGdetermined by the MeNB.

In an embodiment, the MeNB may add, into the SCG configuration message,indication information indicating that the first PScell and the secondPScell share the PUCCH resource of the second PSCell. The indicationinformation may be an explicit indication or an implicit indication. Forexample, when the first SCG is configured, identification information ofthe first PScell and identification information of the second PSCell areboth included for implicit indication. Alternatively, the MeNB may add,into the SCG configuration message, indication information indicatingthat the first SCG and the second SCG share the PUCCH resource of thesecond SCG. The indication information may be an explicit indication oran implicit indication. For example, identification information of thefirst SCG and identification information of the second SCG are bothincluded for implicit indication. Alternatively, the MeNB may instruct,in another manner, the UE to share the PUCCH resource of the firstPSCell and the second PSCell or share the PUCCH resource of the firstSCG and the second SCG. This embodiment of the present disclosure is notlimited thereto.

S530. After receiving the SCG configuration message sent by the MeNB,the UE configures a first PSCell for the newly added SCG or furtherconfigures a second PSCell according to the SCG configurationinformation included in the SCG configuration message. The first PSCellbelongs to the newly configured first SCG, and no PUCCH resource isconfigured. The second PSCell belongs to an SCG that has been configuredor another new SCG that is configured when the new SCG is configured,and a PUCCH resource is configured for the second PSCell.

In an embodiment, the UE determines, according to the indicationinformation included in the SCG configuration message, that information,such as HARQ-ACK, CSI, or an SR related to the first SCG needs to besent in the second PSCell or the second SCG.

In other words, the UE may establish an association relationship betweenthe first SCG or the first PSCell and the second PSCell. The associationrelationship indicates that the PUCCH resource of the first SCG isconfigured in the second PSCell, or that a feedback to the information,such as HARQ-ACK, CSI, or an SR related to the first SCG needs to besent on a PUCCH of the second PSCell.

In this case, the first PSCell is a downlink timing reference cell ofall serving cells in the newly configured first SCG. The second PSCellis a downlink timing reference cell of all serving cells in the secondSCG.

S540. After configuration is completed, the UE sends an SCGconfiguration complete message to the MeNB.

In this way, when the UE needs to send one or more of the information,such as HARQ-ACK, CSI, or an SR related to the first SCG, the UEdetermines to send, by using the PUCCH resource of the second PSCell,the foregoing information.

Therefore, according to the communication method in this embodiment ofthe present disclosure, no PUCCH resource is configured in a firstPSCell in a first SCG, and the first PSCell and a second PSCell share aPUCCH configured in the second PSCell, avoiding that power of the UE isrestricted due to simultaneous PUCCH transmission performed by the UE onexcessive carriers.

FIG. 10 shows a communication method 600 provided by another embodimentof the present disclosure. S610 is similar to S510 and differs from S510in that the first SCG is associated with an SeNB.

When the MeNB determines that the first SCG that needs to be added forthe UE belongs to an SeNB, the MeNB may first negotiate with the SeNB todetermine whether to configure a PUCCH resource in a first PSCell in thefirst SCG.

S620. When determining that the first SCG that needs to be added for theUE belongs to an SeNB, the MeNB sends an SCG establishment requestmessage (or an SeNB configuration request message or an SCG additionrequest message) to the SeNB, where the SCG addition request messagecarries indication information indicating whether to configure a PUCCHresource in the SCG or whether to configure a PUCCH resource in thefirst PSCell. If no PUCCH resource is configured in the first SCG or inthe first PSCell, the SCG addition request message indicates informationabout a second PSCell, and a PUCCH resource is configured for the secondPSCell. The second PSCell is a PSCell of a second SCG that has beenconfigured or a PSCell of another new second SCG that is configured whenthe first SCG is configured.

S630. After receiving the SCG establishment request message, the SeNBdetermines, according to an instruction of the MeNB, whether toconfigure a PUCCH resource in the first SCG or the first PSCell, ordetermines that information, such as HARQ-ACK, CSI, or an SR related tothe first SCG, needs to be sent in the second PSCell.

S640. The SeNB sends an SCG establishment response message to the MeNB.

S650 to S670 are similar to S520 to S540 in the method 500. For brevity,details are not described herein again.

Therefore, compared with the prior-art solution of configuring a PUCCHresource for each SCG, according to the communication method in thisembodiment of the present disclosure, no PUCCH resource is configured ina first PSCell in a first SCG, and the first PSCell and the secondPSCell share a PUCCH configured in the second PSCell, avoiding thatpower on a UE side is restricted due to simultaneous PUCCH transmissionperformed by the UE on excessive carriers.

FIG. 11 shows a communication method 700 provided by another embodimentof the present disclosure.

S710. An MeNB determines that a new first SCG needs to be configured forUE, and that a new first bearer needs to be established in the firstSCG.

S720. The MeNB sends an SCG configuration message to the UE, where theSCG configuration message includes information about a bearer that needsto be established, and the SCG configuration message includes indicationinformation indicating whether to establish a new layer 2 (L2) entityfor the first SCG. The indication information may be explicit indicationinformation or implicit indication information. The L2 entity mayinclude a PDCP entity, an RLC entity, and a MAC entity.

If a new L2 entity needs to be established for the first SCG, whether toestablish one or more of a PDCP entity, an RLC entity, or a MAC entitymay be further indicated. Preferably, the MeNB may instruct the UE toestablish a new MAC entity for the first SCG. The RLC entity and thePDCP entity may be shared with a second SCG.

If no new L2 entity does not need to be established for the first SCG,information about a second SCG that may share the L2 entity with thefirst SCG may be further indicated. The second SCG may be an SCG thathas been established by the UE, or a second SCG that is newlyestablished by the UE as instructed in the SCG configuration message.

Particularly, when the SCG configuration message instructs the UE toestablish a split bearer, the SCG configuration information shouldfurther indicate an identifier of an SCG that should be established by aPDCP entity or an RLC entity of the split bearer. The split bearerindicates that a data packet of the bearer is split and transmitted inthe first SCG and the second SCG. That is, a part of the data packet istransmitted by using the first SCG, and a part of the data packet istransmitted by using the second SCG. If the split bearer is split at aPDCP layer, the SCG configuration information may indicate an identifierof an SCG, that is, the first SCG or the second SCG, corresponding tothe PDCP layer at which the bearer is split. Alternatively, if the splitbearer is split at an RLC layer, the SCG configuration information mayindicate an identifier of an SCG, that is, the first SCG or the secondSCG, corresponding to the RLC layer at which the bearer is split.However, this embodiment of the present disclosure is not limitedthereto.

S730. The UE determines, according to information in the SCGconfiguration message, whether an L2 entity of the first SCG needs to beestablished. Further, if the L2 entity of the first SCG needs to beestablished, which L2 entity of the PDCP entity, the RLC entity, and theMAC entity needs to be established may be determined. Alternatively,when an L2 entity does not need to be established, information about asecond SCG that may share the L2 entity with the first SCG isdetermined. The second SCG is an SCG that has been established by theUE, or a second SCG that is newly established by the UE as instructed inthe SCG configuration message.

For example, after receiving the SCG configuration message, the UEdetermines, according to indication in the SCG configuration message,that a new MAC entity needs to be established for the first SCG, andfurther determines that the first SCG may share a PDCP entity and an RLCentity with the second SCG.

S740. After establishing the first SCG according to the SCGconfiguration message and configuring an L2 entity for the first SCG,the UE sends an SCG configuration complete message to the MeNB.

FIG. 12 shows a communication method 800 provided by another embodimentof the present disclosure. S810 is similar to S710 and differs from S710in that the newly added first SCG is associated with an SeNB. In thiscase, the MeNB may first negotiate with the SeNB to determine whether toestablish a new L2 entity for the first SCG or which L2 entity is to beestablished.

S820. When determining that the first SCG that needs to be added for theUE belongs to an SeNB, the MeNB sends an SCG establishment requestmessage (or an SeNB configuration request message or an SeNB additionrequest message, a specific name of the message is not limited in thepresent disclosure) to the SeNB, where the SCG establishment requestmessage carries indication information indicating whether to establish anew L2 entity for the SCG. If it indicates that no L2 entity isestablished for the first SCG, information about a second SCG that mayshare an L2 entity with the first SCG is indicated. The second SCG is anSCG that has been established by the UE, or a second SCG that is newlyestablished by the UE as instructed in the SCG configuration message.Alternatively, if an L2 entity needs to be established for the firstSCG, that one or more of a MAC entity, an RLC entity, or a PDCP entityneed to be established may be further indicated. If one or more of a MACentity, an RLC entity, or a PDCP entity do not need to be established,information about a second SCG that may share a corresponding entityneeds to be indicated.

S830. After receiving the SCG establishment request message, the SeNBdetermines, according to an instruction of the MeNB, whether toestablish an L2 entity for the first SCG. If the indication informationindicates that no new L2 entity needs to be established for the firstSCG, a second SCG that should share an L2 entity with the first SCG isdetermined according to the indication information. If the indicationinformation indicates some or all L2 entities of a MAC entity, an RLCentity, and a PDCP entity need to be established for the first SCG, acorresponding entity is established for the first SCG.

S840. The SeNB sends an SCG addition request acknowledgment message tothe MeNB.

S850 to S870 are similar to S720 to S740. For brevity, details are notdescribed herein again.

Therefore, compared with the prior-art technical solution ofestablishing an independent L2 entity for each SCG, in the communicationmethod provided in this embodiment of the present disclosure, a firstSCG and the second SCG share one or more L2 entities established in thesecond SCG, avoiding that complexity of UE is increased due to excessiveL2 entities established on a UE side.

FIG. 13 shows a communication method 900 provided by another embodimentof the present disclosure. It is assumed herein that the first SCG andthe second SCG are both associated with an MeNB. If the first SCG andthe second SCG are both associated with an SeNB, the MeNB in FIG. 13 maybe replaced with the SeNB. This embodiment of the present disclosure isnot limited thereto.

S910. The MeNB determines that a new SCG, or referred to as a first SCGherein, needs to be configured for UE.

S920. The MeNB sends an SCG configuration message to the UE, where theSCG configuration message includes indication information indicatingwhether to establish a new security key in the first SCG. The indicationinformation may be explicit indication information or implicitindication information. For example, whether the UE needs to create anew security key in the first SCG is implicitly indicated by whether asecurity configuration parameter (an SCG counter (counter) and/or an SCGencryption algorithm) related to the first SCG is included.

If no new security key needs to be created in the first SCG, the SCGconfiguration message should further indicate information about asecurity key that should be used in the first SCG, such as an indexvalue of the security key and a serial number of the security key. Theinformation about the security key may be one or more of an SCG countervalue, an encryption algorithm, or an intermediate key S-KeNB.

Alternatively, the SCG configuration message may instruct the first SCGand the second SCG to share a security key. The second SCG is an SCGthat has been established by the UE, or a second SCG that is newlyestablished by the UE as instructed in the SCG configuration message.The information about the shared security key may be one or more of anSCG counter value, an encryption algorithm, or an intermediate keyS-KeNB of the second SCG.

Alternatively, the SCG configuration message may indicate that the firstSCG should share a PDCP entity with the second SCG for the establishedbearer. The PDCP entity has a security key management function.Therefore, the UE may be implicitly instructed to use a security key thesame as that of the second SCG when the UE performs data transmission inthe first SCG.

S930. After receiving the SCG configuration message, the UE determines,according to the indication information in the SCG configurationmessage, whether to create a new security key in the first SCG.Alternatively, if no new security key needs to be created for the firstSCG, an available security key is determined. For example, an availablesecurity key is determined according to an index of a security key inthe SCG configuration message. Subsequently, when encrypting data, theUE may generate an encryption key by using the indicated security key,encrypt data that needs to be encrypted, and then transmit the data.

Alternatively, it is determined according to SCG configuration messagethat a security key may be shared with the second SCG. Subsequently,when performing data transmission in the first SCG, the UE generates anencryption key (Kenc) by using a security key the same as that of thesecond SCG, encrypts data that needs to be encrypted, and then transmitsthe data.

Alternatively, according to information, indicated in the SCGconfiguration message, that a PDCP entity is shared with the second SCG,the UE determines that the first SCG may share a security key with thesecond SCG. Therefore, when performing data transmission in the firstSCG, the UE generates an encryption key Kenc by using a security key thesame as that of the second SCG, encrypts data that needs to beencrypted, and then transmits the data.

S940. After completing configuration on the first SCG according to theSCG configuration message, the UE sends an SCG configuration completemessage to the MeNB.

Therefore, according to the communication method in this embodiment ofthe present disclosure, a first SCG and the second SCG share a key,avoiding increasing complexity of UE due to excessive security keysmanaged on a UE side.

FIG. 14 shows a communication method 1000 provided by another embodimentof the present disclosure. It is assumed herein that the first SCG andthe second SCG are both associated with an MeNB. If the first SCG andthe second SCG are both associated with an SeNB, the MeNB in FIG. 14 maybe replaced with the SeNB. This embodiment of the present disclosure isnot limited thereto.

S1001. The MeNB determines that one or more SCGs need to be configuredfor UE, and determines whether the one or more SCGs may belong to a sameTAG. The TAG includes one or more serving cells that may share one TAvalue. That is, all cells in one TAG may use a same TA value.

S1002. The MeNB sends an SCG configuration message to the UE, where theSCG configuration message includes TAG information of a serving cell inthe SCG, that is, information about a TAG to which the serving cell inthe SCG belongs. When multiple SCGs are configured together, the SCGconfiguration information may include information about a PSCell of eachSCG. If PSCells in the multiple SCGs that are configured together belongto the same TAG, the MeNB may configure a random access resource onlyfor one of the PSCells.

S1003. After receiving the SCG configuration message, the UE determinesinformation about a TAG to which a PSCell in the SCG belongs. If the TAGof the PSCell is an existing TAG, the UE skips performing random accessin the PSCell, but directly performs uplink transmission by using a TAvalue corresponding to the TAG. Otherwise, the UE performs random accessin the PSCell in the SCG to obtain a new TA value.

When multiple SCGs are added into the SCG configuration messagetogether, the UE determines whether PSCells in the multiple SCGs belongto a same TAG. If the PSCells in the multiple SCGs belong to the sameTAG, the UE selects a PSCell in one SCG to perform random access toobtain a TA value of the TAG to which the PSCell in the SCG belongs.Otherwise, if PSCells in at least two SCGs of the PSCells in themultiple SCGs do not belong to the same TAG, the UE sequentiallyperforms random access in different PSCells. In an embodiment, a mannerin which the UE chooses to preferentially perform random access in whichPSCell may be making a selection in an order based on identifiers of thePSCells, and then sequentially performing random access in multiplePSCells, to obtain TA values of corresponding TAGs. Alternatively, theUE may choose, according to configuration of SCGs, a PSCell for which arandom access resource has been configured to perform random access, toobtain a TA value of a corresponding TAG.

Therefore, compared with the technical solution of performing randomaccess in each PSCell in DC, according to the communication method inthis embodiment of the present disclosure, UE can be prevented fromperforming unnecessary random access. If multiple SCGs are configured,the UE can also be prevented from performing excessive random access,further avoiding that power of the UE is restricted due to random accessperformed in multiple PScells by the UE.

It should be noted that the examples in FIG. 9 and FIG. 14 are used tohelp a person skilled in the art better understand this embodiment ofthe present disclosure, rather than to limit the scope of theembodiments of the present disclosure. Apparently, a person skilled inthe art may make various equivalent modifications or changes accordingto the examples provided in FIG. 9 and FIG. 14, and such modificationsor changes also fall within the scope of the embodiments of the presentdisclosure.

It should be understood that sequence numbers of the foregoing processesdo not mean execution sequences. The execution sequences of theprocesses should be determined according to functions and internal logicof the processes, and should not be construed as any limitation on theimplementation processes of the embodiments of the present disclosure.

It should also be understood that the term “a PUCCH of a second SCG” mayrefer to “a PUCCH used by a second SCG”, and may include a PUCCHallocated by a network side to the second SCG as described above, or mayinclude a PUCCH shared by another cell group with the second SCG. Forexample, the network side allocates a same PUCCH to the second SCG andthe another cell group. This is not limited in the embodiments of thepresent disclosure.

It should also be understood that the term “a layer 2 functional entityof a second SCG” may refer to “a layer 2 functional entity establishedin a second SCG”, and may include a layer 2 functional entity that isestablished by user equipment in the second SCG and that corresponds tothe second SCG as described above. This is not limited in theembodiments of the present disclosure.

It should also be understood that the term “a security configurationparameter of a second cell group” may refer to “a security configurationparameter used by a second cell group”, and may include a securityconfiguration parameter particularly allocated by a network side to thesecond cell group for user equipment as described above, or may includea security configuration parameter shared by another cell group with thesecond cell group. For example, the network side allocates a samesecurity configuration parameter to the another cell group and thesecond cell group, or the network side allocate a security configurationparameter to the another cell group. This is not limited in theembodiments of the present disclosure.

It should also be understood that the term “a timing advance value of asecond cell group” may refer to “a timing advance value used by a secondcell group”, and may include a timing advance value obtained by userequipment by performing a random access procedure in the second cellgroup, or may include a timing advance value obtained by the userequipment in another cell group, and the second cell group shares thetiming advance value with the another cell group. This is not limited inthe embodiments of the present disclosure.

With reference to FIG. 2 to FIG. 14, the communication methods providedby the embodiments of the present disclosure are described in detailabove. With reference to FIG. 15 to FIG. 22, a network device, userequipment, and a communications system according to embodiments of thepresent disclosure are described below.

FIG. 15 shows a network device 1100 provided by an embodiment of thepresent disclosure. The network device may be a base station, a basestation controller, or another network side device. This is not limitedin this embodiment of the present disclosure. As shown in FIG. 15, thenetwork device 1100 includes a determining unit 1110 configured todetermine to allocate a first SCG to user equipment, and a sending unit1120 configured to send first configuration indication information tothe user equipment, where the first configuration indication informationis used to indicate at least one type of the following configuration ofthe allocated first SCG determined by the determining unit 1110transmitting uplink control information related to a cell in the firstSCG by using a PUCCH of a first cell, where the first cell belongs to asecond SCG of the user equipment, or processing data transmission on atleast one cell in the first SCG by using a layer 2 functional entitylocated in the second SCG.

Therefore, according to the network device in this embodiment of thepresent disclosure, through configuration, uplink control informationrelated to a cell in a first SCG of user equipment is transmitted byusing a PUCCH of a first cell, where the first cell belongs to a secondSCG of the user equipment, and/or data transmission on at least one cellin the first SCG is processed by using a layer 2 functional entitylocated in the second SCG, so that a quantity of parameters maintainedby the user equipment can be reduced, thereby reducing complexity of theuser equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

Optionally, the first cell is a PSCell in second SCG of the userequipment.

The uplink control information includes at least one of the followinginformation acknowledgment information ACK, negative acknowledgmentinformation NACK, or CSI.

In another optional embodiment, the first configuration indicationinformation includes at least one of the following informationidentification information of the second SCG of the user equipment oridentification information of the first cell.

In another optional embodiment, the layer 2 functional entity includesat least one of a Media Access Control entity, a Radio Link Controlentity, or a Packet Data Convergence Protocol entity.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing, in the second SCGof the user equipment, at least one of a Packet Data ConvergenceProtocol entity or a Radio Link Control entity that corresponds to abearer of the first SCG.

Correspondingly, the processing data transmission on at least one cellin the first SCG by using a layer 2 functional entity located in thesecond SCG includes processing data transmission on the bearer of thefirst SCG by using at least one of the Packet Data Convergence Protocolentity or the Radio Link Control entity that is established in thesecond SCG and that corresponds to the bearer.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing a split bearer ofthe first SCG and the second SCG and indicate a SCG, used to perform asplit operation, in the first SCG and the second SCG.

In another optional embodiment, the network device is a MeNB, the userequipment has at least two serving base stations including the MeNB anda first SeNB, and the first SCG is associated with the first SeNB. Inthis case, the sending unit is further configured to, before sending thefirst configuration indication information to the user equipment, sendsecond configuration indication information to the first SeNB, where thesecond configuration indication information is used to indicate aconfiguration parameter of the first SCG that is determined by the MeNB,and the configuration parameter includes at least one of a PUCCH of thecell in the first SCG or a layer 2 functional entity corresponding tothe data transmission on the at least one cell in the first SCG.

Correspondingly, the MeNB further includes a second receiving unitconfigured to receive a configuration response message that is sent bythe first SeNB according to the second configuration indicationinformation sent by the sending unit, and the sending unit is furtherconfigured to send the first configuration indication information to theuser equipment according to the configuration response message receivedby the second receiving unit.

In another optional embodiment, all cell groups configured for the userequipment are associated with a same serving base station of the userequipment.

In another optional embodiment, the user equipment has multiple servingbase stations, and the first SCG and the second SCG are associated withdifferent base stations.

In another optional embodiment, the configuration response message isused to indicate a configuration parameter of the first SCG that isdetermined by the first SeNB according to the second configurationindication information.

Correspondingly, the sending unit includes a determining subunitconfigured to determine at least one type of the following configurationaccording to the configuration response message received by the secondreceiving unit transmitting the uplink control information of the cellin the first SCG by using the PUCCH of the first cell, or processing thedata transmission on the at least one cell in the first SCG by using thelayer 2 functional entity located in the second SCG.

In another optional embodiment, the first configuration indicationinformation is further used to indicate at least one type of thefollowing configuration, in a data transmission process in the at leastone cell in the first SCG, generating an encryption key by using asecurity configuration parameter of the second SCG of the userequipment, or in a data transmission process in the at least one cell inthe first SCG, performing uplink timing adjustment by using a timingadvance value of the second SCG of the user equipment.

The network device 1100 according to this embodiment of the presentdisclosure may correspond to the network device in the communicationmethods according to the embodiments of the present disclosure, and theforegoing and other operations and/or functions of the modules in thenetwork device 1100 respectively implement corresponding procedures ofthe methods in FIG. 2 and FIG. 9 to FIG. 14. For brevity, details arenot described herein again.

Therefore, according to the network device in this embodiment of thepresent disclosure, through configuration, uplink control informationrelated to a cell in a first SCG of user equipment is transmitted byusing a PUCCH of a first cell, where the first cell belongs to a secondSCG of the user equipment, and/or data transmission on at least one cellin the first SCG is processed by using a layer 2 functional entitylocated in the second SCG, so that a quantity of parameters maintainedby the user equipment can be reduced, thereby reducing complexity of theuser equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

FIG. 16 shows a network device 1200 provided by another embodiment ofthe present disclosure. The network device 1200 may be a base station, abase station controller, or another network side device. As shown inFIG. 16, the network device 1200 includes a determining unit 1210configured to determine to allocate a first cell group to userequipment, where the first cell group is a SCG, and a sending unit 1220configured to send first configuration indication information to theuser equipment, where the first configuration indication information isused to indicate at least one type of the following configuration of theallocated first cell group determined by the determining unit 1210, in adata transmission process in at least one cell in the first cell group,generating an encryption key by using a security configuration parameterof a second cell group of the user equipment, or in a data transmissionprocess in at least one cell in the first cell group, performing uplinktiming adjustment by using a timing advance value of a second cell groupof the user equipment.

Therefore, according to the network device in this embodiment of thepresent disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

Optionally, the first cell group and the second cell group areassociated with a same serving base station of the user equipment.

Optionally, the second cell group is a MCG or a SCG.

In an optional embodiment, the serving base stations of the userequipment include a MeNB and at least one SeNB. The second cell group isa SCG, and the first cell group and the second cell group are bothassociated with a same SeNB of the user equipment.

In another optional embodiment, the security configuration parameterincludes at least one of the following parameters a SCG counter, a SCGintermediate key, an index value of a SCG intermediate key, or a serialnumber of a SCG intermediate key.

In another optional embodiment, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, generating an encryption key byusing a security configuration parameter of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate processing data transmission on the at least onecell in the first cell group by using a Packet Data Convergence Protocolentity located in the second cell group.

In another optional embodiment, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate that the first cell group of the user equipment andthe second cell group of the user equipment belong to a same TAG, or thefirst configuration indication information is used to indicate that aPSCell in the first cell group of the user equipment and a PSCell or aPCell in the second cell group of the user equipment belong to a sameTAG.

In another optional embodiment, the first configuration indicationinformation is further used to indicate that the first cell group doesnot have a random access resource. A random access resource isconfigured for the second cell group, and the timing advance value ofthe second cell group is obtained by the user equipment by performing arandom access procedure in the second cell group by using the randomaccess resource.

In another optional embodiment, the network device 1200 further includesa first receiving unit configured to receive a configuration completemessage that is sent by the user equipment according to the firstconfiguration indication information.

In another optional embodiment, the network device is a first SeNBassociated with both the first cell group and the second cell group, andthe user equipment has at least two serving base stations including aMeNB and the first SeNB.

Correspondingly, the first SeNB further includes a second receiving unitconfigured to, before the sending unit sends the first configurationindication information to the user equipment, receive secondconfiguration indication information sent by the MeNB, where the secondconfiguration indication information is used to instruct the first SeNBto allocate the first cell group to the user equipment, and thedetermining unit is further configured to determine, according to thesecond configuration indication information received by the secondreceiving unit, to allocate the first cell group to the user equipment.

The network device 1200 according to this embodiment of the presentdisclosure may correspond to the network device in the communicationmethods according to the embodiments of the present disclosure, and theforegoing and other operations and/or functions of the modules in thenetwork device 1200 respectively implement corresponding procedures ofthe methods in FIG. 6 and FIG. 9 to FIG. 14. For brevity, details arenot described herein again.

Therefore, according to the network device in this embodiment of thepresent disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

FIG. 17 shows user equipment 1300 provided by an embodiment of thepresent disclosure. The user equipment 1300 includes a receiving unit1310 configured to receive first configuration indication informationsent by a network device, where the first configuration indicationinformation is used to indicate at least one type of the followingconfiguration transmitting uplink control information related to a cellin a first SCG of the user equipment by using a PUCCH of a first cell,where the first cell belongs to a second SCG of the user equipment, orprocessing data transmission on at least one cell in a first SCG of theuser equipment by using a layer 2 functional entity located in thesecond SCG, and a configuration unit 1320 configured to configure thefirst SCG according to the first configuration indication informationreceived by the receiving unit 1310.

Therefore, according to the user equipment in this embodiment of thepresent disclosure, through configuration, uplink control informationrelated to a cell in a first SCG of user equipment is transmitted byusing a PUCCH of a first cell, where the first cell belongs to a secondSCG of the user equipment, and/or data transmission on at least one cellin the first SCG is processed by using a layer 2 functional entitylocated in the second SCG, so that a quantity of parameters maintainedby the user equipment can be reduced, thereby reducing complexity of theuser equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

Optionally, the first cell is a PSCell in second SCG of the userequipment.

The uplink control information includes at least one of the followinginformation acknowledgment information ACK, negative acknowledgmentinformation NACK, or CSI.

Optionally, the first configuration indication information includes atleast one of the following information identification information of thesecond SCG of the user equipment or identification information of thefirst cell.

In another optional embodiment, a PUCCH is configured for a PSCell inthe second SCG. The first configuration indication information is usedto indicate performing the data transmission on the at least one cell inthe first SCG by using the PUCCH configured for the PSCell in the secondSCG.

In another optional embodiment, the layer 2 functional entity includesat least one of a Media Access Control entity, a Radio Link Controlentity, or a Packet Data Convergence Protocol entity.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing, in the second SCG,at least one of a Packet Data Convergence Protocol entity or a RadioLink Control entity that corresponds to a bearer of the first SCG.

The processing data transmission on at least one cell in a first SCG byusing a layer 2 functional entity established in the second SCG of theuser equipment includes processing data transmission on the bearer ofthe first SCG by using at least one of the Packet Data ConvergenceProtocol entity or the Radio Link Control entity that is established inthe second SCG and that corresponds to the bearer.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing a split bearer ofthe first SCG and the second SCG and indicate a SCG, used to perform asplit operation, in the first SCG and the second SCG.

In another optional embodiment, the user equipment 1300 further includesa sending unit configured to send a configuration complete message tothe network device.

In another optional embodiment, all cell groups configured for the userequipment are associated with a same base station of the user equipment.

In another optional embodiment, the user equipment has multiple servingbase stations, and the first SCG and the second SCG are associated withdifferent base stations.

In another optional embodiment, the first configuration indicationinformation is further used to indicate at least one type of thefollowing configuration, in a data transmission process in the at leastone cell in the first SCG, generating an encryption key by using asecurity configuration parameter of the second SCG of the userequipment, or in a data transmission process in the at least one cell inthe first SCG, performing uplink timing adjustment by using a timingadvance value of the second SCG of the user equipment.

The user equipment 1300 according to this embodiment of the presentdisclosure may correspond to the network device in the communicationmethods according to the embodiments of the present disclosure, and theforegoing and other operations and/or functions of the modules in theuser equipment 1300 respectively implement corresponding procedures ofthe methods in FIG. 7 and FIG. 9 to FIG. 14. For brevity, details arenot described herein again.

Therefore, according to the user equipment in this embodiment of thepresent disclosure, through configuration, uplink control informationrelated to a cell in a first SCG of user equipment is transmitted byusing a PUCCH of a first cell, where the first cell belongs to a secondSCG of the user equipment, and/or data transmission on at least one cellin the first SCG is processed by using a layer 2 functional entitylocated in the second SCG, so that a quantity of parameters maintainedby the user equipment can be reduced, thereby reducing complexity of theuser equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

FIG. 18 shows user equipment 1400 provided by another embodiment of thepresent disclosure. The user equipment 1400 includes a receiving unit1410 configured to receive first configuration indication informationsent by a network device, where the first configuration indicationinformation is used to indicate at least one type of the followingconfiguration, in a data transmission process in at least one cell in afirst cell group of the user equipment, generating an encryption key byusing a security configuration parameter of a second cell group of theuser equipment, or in a data transmission process in at least one cellin the first cell group, performing uplink timing adjustment by using atiming advance value of a second cell group of the user equipment, and aconfiguration unit 1420 configured to configure the first cell groupaccording to the first configuration indication information received bythe receiving unit 1410.

Therefore, according to user equipment in this embodiment of the presentdisclosure, through configuration, in a data transmission process in atleast one cell in a first cell group of user equipment, an encryptionkey is generated by using a security configuration parameter of a secondcell group of the user equipment, and/or in a data transmission processin at least one cell in the first cell group, uplink timing adjustmentis performed by using a timing advance value of the second cell group,so that the user equipment does not need to maintain a large quantity ofsecurity configuration parameters or timing advance values, therebyreducing complexity of the user equipment, and improving feasibility ofa system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

Optionally, the first cell group and the second cell group areassociated with a same serving base station of the user equipment.

In another optional embodiment, the second cell group is a MCG or a SCG.

In another optional embodiment, serving base stations of the userequipment include a MeNB and at least one SeNB. The second cell group isa SCG, and the first cell group and the second cell group are bothassociated with a SeNB of the user equipment.

In another optional embodiment, the security configuration parameterincludes at least one of the following parameters a SCG counter, a SCGintermediate key, an index value of a SCG intermediate key, or a serialnumber of a SCG intermediate key.

In another optional embodiment, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, generating an encryption key byusing a security configuration parameter of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate processing data transmission on the at least onecell in the first cell group by using a Packet Data Convergence Protocolentity located in the second cell group.

In this case, the configuration unit 1420 is further configured to,according to that the data transmission on the at least one cell in thefirst cell group is processed by using the Packet Data ConvergenceProtocol entity located in the second cell group, which is indicated inthe first configuration indication information, determine to generate,in the data transmission process in the at least one cell in the firstcell group, an encryption key by using a security configurationparameter of the second cell group of the user equipment.

In another optional embodiment, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate that the first cell group of the user equipment andthe second cell group of the user equipment belong to a same TAG, or thefirst configuration indication information is used to indicate that aPSCell in the first cell group of the user equipment and a PSCell or aPCell in the second cell group of the user equipment belong to a sameTAG.

In this case, the configuration unit 1420 is further configured to,according to that the first cell group and the second cell group belongto the same TAG or the PSCell in the first cell group and the PSCell orthe PCell in the second cell group belong to the same TAG, which isindicated in the first configuration indication information, determineto perform, in the data transmission process in the at least one cell inthe first cell group, uplink timing adjustment by using the timingadvance value of the second cell group of the user equipment.

In another optional embodiment, the receiving unit 1410 is furtherconfigured to receive second configuration indication information sentby the network device, where the second configuration indicationinformation is used to indicate a random access resource allocated bythe network device to the second cell group.

Correspondingly, the user equipment 1400 further includes a randomaccess unit configured to perform a random access process in the secondcell group according to the second configuration indication informationreceived by the receiving unit 1410, to obtain a timing advance value ofthe second cell group, and a communications unit configured tocommunicate with the serving base station of the user equipment in thefirst cell group according to the timing advance value of the secondcell group that is obtained by the random access unit.

In another optional embodiment, the user equipment 1400 further includesa sending unit configured to send a configuration complete message tothe network device.

The user equipment 1400 according to this embodiment of the presentdisclosure may correspond to the user equipment in the communicationmethods according to the embodiments of the present disclosure, and theforegoing and other operations and/or functions of the modules in theuser equipment 1400 respectively implement corresponding procedures ofthe methods in FIG. 8 to FIG. 14. For brevity, details are not describedherein again.

Therefore, according to the user equipment in this embodiment of thepresent disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

FIG. 19 shows a network device 1500 provided by an embodiment of thepresent disclosure. The network device may be a base station, a basestation controller, or another network side device. This is not limitedin this embodiment of the present disclosure. As shown in FIG. 19, thenetwork device 1500 includes a processor 1510 configured to determine toallocate a first SCG to user equipment, and a transmitter 1520configured to send first configuration indication information to theuser equipment, where the first configuration indication information isused to indicate at least one type of the following configuration of theallocated first SCG determined by the processor 1510 transmitting uplinkcontrol information related to a cell in the first SCG by using a PUCCHof a first cell, where the first cell belongs to a second SCG of theuser equipment, or processing data transmission on at least one cell inthe first SCG by using a layer 2 functional entity located in the secondSCG.

Therefore, according to the network device in this embodiment of thepresent disclosure, through configuration, uplink control informationrelated to a cell in a first SCG of user equipment is transmitted byusing a PUCCH of a first cell, where the first cell belongs to a secondSCG of the user equipment, and/or data transmission on at least one cellin the first SCG is processed by using a layer 2 functional entitylocated in the second SCG, so that a quantity of parameters maintainedby the user equipment can be reduced, thereby reducing complexity of theuser equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

It should be understood that in this embodiment of the presentdisclosure, the processor 1510 may be a central processing unit (CPU),or the processor 1510 may be another general purpose processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field-programmable gate array (FPGA), or anotherprogrammable logic device, discrete gate or transistor logic device, ordiscrete hardware component. The general purpose processor may be amicroprocessor or the processor may be any conventional processor or thelike.

The network device may further include a memory. The memory may includea read-only memory and a random access memory and provide an instructionand data to the processor 1510. A part of the memory may further includea non-volatile random access memory. For example, the memory may furtherstore device type information.

The network device may further include a bus system. In addition toincluding a data bus, the bus system may further include a power bus, acontrol bus, a state signal bus, and the like. However, for cleardescription, all buses are marked as the bus system in the figure.

In an implementation process, steps of the foregoing methods may beaccomplished by using an integrated logic circuit of hardware in theprocessor 1510 or an instruction in a form of software. The steps of themethod that are disclosed in the embodiments of the present disclosuremay be directly performed and completed by a hardware processor orperformed and completed by a combination of hardware and softwaremodules in the processor. The software module may be located in a maturestorage medium in the art, such as a random access memory, a flashmemory, a read-only memory, a programmable read-only memory, an electricerasable programmable memory, or a register. The storage medium islocated in the memory, and the processor 1510 reads information in thememory and completes the steps in the foregoing methods in combinationwith hardware of the processor 1510. To avoid repetition, details arenot described herein again.

Optionally, the first cell is a PSCell in second SCG of the userequipment.

The uplink control information includes at least one of the followinginformation acknowledgment information ACK, negative acknowledgmentinformation NACK, or CSI.

In another optional embodiment, the first configuration indicationinformation includes at least one of the following informationidentification information of the second SCG of the user equipment oridentification information of the first cell.

In another optional embodiment, the layer 2 functional entity includesat least one of a Media Access Control entity, a Radio Link Controlentity, or a Packet Data Convergence Protocol entity.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing, in the second SCGof the user equipment, at least one of a Packet Data ConvergenceProtocol entity or a Radio Link Control entity that corresponds to abearer of the first SCG.

Correspondingly, the processing data transmission on at least one cellin the first SCG by using a layer 2 functional entity located in thesecond SCG includes processing data transmission on the bearer of thefirst SCG by using at least one of the Packet Data Convergence Protocolentity or the Radio Link Control entity that is established in thesecond SCG and that corresponds to the bearer.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing a split bearer ofthe first SCG and the second SCG and indicate a SCG, used to perform asplit operation, in the first SCG and the second SCG.

In another optional embodiment, the network device is a MeNB, the userequipment has at least two serving base stations including the MeNB anda first SeNB, and the first SCG is associated with the first SeNB. Inthis case, the transmitter is further configured to, before sending thefirst configuration indication information to the user equipment, sendsecond configuration indication information to the first SeNB, where thesecond configuration indication information is used to indicate aconfiguration parameter of the first SCG that is determined by the MeNB,and the configuration parameter includes at least one of a PUCCH of thecell in the first SCG or a layer 2 functional entity corresponding tothe data transmission on the at least one cell in the first SCG.

Correspondingly, the MeNB further includes a second receiver configuredto receive a configuration response message that is sent by the firstSeNB according to the second configuration indication information sentby the transmitter, and the transmitter is further configured to sendthe first configuration indication information to the user equipmentaccording to the configuration response message received by the secondreceiver.

In another optional embodiment, all cell groups configured for the userequipment are associated with a same serving base station of the userequipment.

In another optional embodiment, the user equipment has multiple servingbase stations, and the first SCG and the second SCG are associated withdifferent base stations.

In another optional embodiment, the configuration response message isused to indicate a configuration parameter of the first SCG that isdetermined by the first SeNB according to the second configurationindication information.

Correspondingly, the processor is further configured to determine atleast one type of the following configuration according to theconfiguration response message received by the receiver transmitting theuplink control information of the cell in the first SCG by using thePUCCH of the first cell, or processing the data transmission on the atleast one cell in the first SCG by using the layer 2 functional entitylocated in the second SCG.

In another optional embodiment, the first configuration indicationinformation is further used to indicate at least one type of thefollowing configuration, in a data transmission process in the at leastone cell in the first SCG, generating an encryption key by using asecurity configuration parameter of the second SCG of the userequipment, or in a data transmission process in the at least one cell inthe first SCG, performing uplink timing adjustment by using a timingadvance value of the second SCG of the user equipment.

The network device 1500 according to this embodiment of the presentdisclosure may correspond to the network device in the communicationmethods according to the embodiments of the present disclosure, and theforegoing and other operations and/or functions of the modules in thenetwork device 1500 respectively implement corresponding procedures ofthe methods in FIG. 2 and FIG. 9 to FIG. 14. For brevity, details arenot described herein again.

Therefore, according to the network device in this embodiment of thepresent disclosure, through configuration, uplink control informationrelated to a cell in a first SCG of user equipment is transmitted byusing a PUCCH of a first cell, where the first cell belongs to a secondSCG of the user equipment, and/or data transmission on at least one cellin the first SCG is processed by using a layer 2 functional entitylocated in the second SCG, so that a quantity of parameters maintainedby the user equipment can be reduced, thereby reducing complexity of theuser equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

FIG. 20 shows a network device 1600 provided by another embodiment ofthe present disclosure. The network device may 1600 be a base station, abase station controller, or another network side device. As shown inFIG. 20, the network device 1600 includes a processor 1610 configured todetermine to allocate a first cell group to user equipment, where thefirst cell group is a SCG, and a transmitter 1620 configured to sendfirst configuration indication information to the user equipment, wherethe first configuration indication information is used to instruct theprocessor 1610 to determine at least one type of the followingconfiguration of the allocated first cell group, in a data transmissionprocess in at least one cell in the first cell group, generating anencryption key by using a security configuration parameter of a secondcell group of the user equipment, or in a data transmission process inat least one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment.

Therefore, according to the network device in this embodiment of thepresent disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

It should be understood that in this embodiment of the presentdisclosure, the processor 1610 may be a central processing unit (CPU),or the processor 1610 may be another general purpose processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field-programmable gate array (FPGA), or anotherprogrammable logic device, discrete gate or transistor logic device, ordiscrete hardware component. The general purpose processor may be amicroprocessor or the processor may be any conventional processor or thelike.

The network device may further include a memory. The memory may includea read-only memory and a random access memory and provide an instructionand data to the processor 1610. A part of the memory may further includea non-volatile random access memory. For example, the memory may furtherstore device type information.

The network device may further include a bus system. In addition toincluding a data bus, the bus system may further include a power bus, acontrol bus, a state signal bus, and the like. However, for cleardescription, all buses are marked as the bus system in the figure.

In an implementation process, steps of the foregoing methods may beaccomplished by using an integrated logic circuit of hardware in theprocessor 1610 or an instruction in a form of software. The steps of themethod that are disclosed in the embodiments of the present disclosuremay be directly performed and completed by a hardware processor orperformed and completed by a combination of hardware and softwaremodules in the processor. The software module may be located in a maturestorage medium in the art, such as a random access memory, a flashmemory, a read-only memory, a programmable read-only memory, an electricerasable programmable memory, or a register. The storage medium islocated in the memory, and the processor 1610 reads information in thememory and completes the steps in the foregoing methods in combinationwith hardware of the processor 1610. To avoid repetition, details arenot described herein again.

Optionally, the first cell group and the second cell group areassociated with a same serving base station of the user equipment.

Optionally, the second cell group is a MCG or a SCG.

In an optional embodiment, the serving base stations of the userequipment include a MeNB and at least one SeNB. The second cell group isa SCG, and the first cell group and the second cell group are bothassociated with a same SeNB of the user equipment.

In another optional embodiment, the security configuration parameterincludes at least one of the following parameters a SCG counter, a SCGintermediate key, an index value of a SCG intermediate key, or a serialnumber of a SCG intermediate key.

In another optional embodiment, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, generating an encryption key byusing a security configuration parameter of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate processing data transmission on the at least onecell in the first cell group by using a Packet Data Convergence Protocolentity located in the second cell group.

In another optional embodiment, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate that the first cell group of the user equipment andthe second cell group of the user equipment belong to a same TAG, or thefirst configuration indication information is used to indicate that aPSCell in the first cell group of the user equipment and a PSCell or aPCell in the second cell group of the user equipment belong to a sameTAG.

In another optional embodiment, the first configuration indicationinformation is further used to indicate that the first cell group doesnot have a random access resource. A random access resource isconfigured for the second cell group, and the timing advance value ofthe second cell group is obtained by the user equipment by performing arandom access procedure in the second cell group by using the randomaccess resource.

In another optional embodiment, the network device 1600 further includesa receiver configured to receive a configuration complete message thatis sent by the user equipment according to the first configurationindication information.

In another optional embodiment, the network device is a first SeNBassociated with both the first cell group and the second cell group, andthe user equipment has at least two serving base stations including aMeNB and the first SeNB. In this case, the first SeNB further includes areceiver configured to, before the transmitter sends the firstconfiguration indication information to the user equipment, receivesecond configuration indication information sent by the MeNB, where thesecond configuration indication information is used to instruct thefirst SeNB to allocate the first cell group to the user equipment, andcorrespondingly, the processor is further configured to determine,according to the second configuration indication information received bythe receiver, to allocate the first cell group to the user equipment.

The network device 1600 according to this embodiment of the presentdisclosure may correspond to the network device in the communicationmethods according to the embodiments of the present disclosure, and theforegoing and other operations and/or functions of the modules in thenetwork device 1600 respectively implement corresponding procedures ofthe methods in FIG. 6 and FIG. 9 to FIG. 14. For brevity, details arenot described herein again.

Therefore, according to the network device in this embodiment of thepresent disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

FIG. 21 shows user equipment 1700 provided by an embodiment of thepresent disclosure. The user equipment 1700 includes a receiver 1710configured to receive first configuration indication information sent bya network device, where the first configuration indication informationis used to indicate at least one type of the following configurationtransmitting uplink control information related to a cell in a first SCGof the user equipment by using a PUCCH of a first cell, where the firstcell belongs to a second SCG of the user equipment, or processing datatransmission on at least one cell in a first SCG of the user equipmentby using a layer 2 functional entity located in the second SCG, and aprocessor 1720 configured to configure the first SCG according to thefirst configuration indication information received by the receiver1710.

Therefore, according to the user equipment in this embodiment of thepresent disclosure, through configuration, uplink control informationrelated to a cell in a first SCG of user equipment is transmitted byusing a PUCCH of a first cell, where the first cell belongs to a secondSCG of the user equipment, and/or data transmission on at least one cellin the first SCG is processed by using a layer 2 functional entitylocated in the second SCG, so that a quantity of parameters maintainedby the user equipment can be reduced, thereby reducing complexity of theuser equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

It should be understood that in this embodiment of the presentdisclosure, the processor 1720 may be a central processing unit (CPU),or the processor 1720 may be another general purpose processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field-programmable gate array (FPGA), or anotherprogrammable logic device, discrete gate or transistor logic device, ordiscrete hardware component. The general purpose processor may be amicroprocessor or the processor may be any conventional processor or thelike.

The network device may further include a memory. The memory may includea read-only memory and a random access memory and provide an instructionand data to the processor 1720. A part of the memory may further includea non-volatile random access memory. For example, the memory may furtherstore device type information.

The network device may further include a bus system. In addition toincluding a data bus, the bus system may further include a power bus, acontrol bus, a state signal bus, and the like. However, for cleardescription, all buses are marked as the bus system in the figure.

In an implementation process, steps of the foregoing methods may beaccomplished by using an integrated logic circuit of hardware in theprocessor 1720 or an instruction in a form of software. The steps of themethod that are disclosed in the embodiments of the present disclosuremay be directly performed and completed by a hardware processor orperformed and completed by a combination of hardware and softwaremodules in the processor. The software module may be located in a maturestorage medium in the art, such as a random access memory, a flashmemory, a read-only memory, a programmable read-only memory, an electricerasable programmable memory, or a register. The storage medium islocated in the memory, and the processor 1720 reads information in thememory and completes the steps in the foregoing methods in combinationwith hardware of the processor 1720. To avoid repetition, details arenot described herein again.

Optionally, the first cell is a PSCell in second SCG of the userequipment.

The uplink control information includes at least one of the followinginformation acknowledgment information ACK, negative acknowledgmentinformation NACK, or CSI.

Optionally, the first configuration indication information includes atleast one of the following information identification information of thesecond SCG of the user equipment or identification information of thefirst cell.

In another optional embodiment, a PUCCH is configured for a PSCell inthe second SCG. The first configuration indication information is usedto indicate performing the data transmission on the at least one cell inthe first SCG by using the PUCCH configured for the PSCell in the secondSCG.

In another optional embodiment, the layer 2 functional entity includesat least one of a Media Access Control entity, a Radio Link Controlentity, or a Packet Data Convergence Protocol entity.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing, in the second SCG,at least one of a Packet Data Convergence Protocol entity or a RadioLink Control entity that corresponds to a bearer of the first SCG.

Correspondingly, the processing data transmission on at least one cellin a first SCG by using a layer 2 functional entity established in thesecond SCG of the user equipment includes processing data transmissionon the bearer of the first SCG by using at least one of the Packet DataConvergence Protocol entity or the Radio Link Control entity that isestablished in the second SCG and that corresponds to the bearer.

In another optional embodiment, the first configuration indicationinformation is further used to indicate establishing a split bearer ofthe first SCG and the second SCG and indicate a SCG, used to perform asplit operation, in the first SCG and the second SCG.

In another optional embodiment, the user equipment 1700 further includesa transmitter configured to send a configuration complete message to thenetwork device.

In another optional embodiment, all cell groups configured for the userequipment are associated with a same base station of the user equipment.

In another optional embodiment, the user equipment has multiple servingbase stations, and the first SCG and the second SCG are associated withdifferent base stations.

In another optional embodiment, the first configuration indicationinformation is further used to indicate at least one type of thefollowing configuration, in a data transmission process in the at leastone cell in the first SCG, generating an encryption key by using asecurity configuration parameter of the second SCG of the userequipment, or in a data transmission process in the at least one cell inthe first SCG, performing uplink timing adjustment by using a timingadvance value of the second SCG of the user equipment.

The user equipment 1700 according to this embodiment of the presentdisclosure may correspond to the network device in the communicationmethods according to the embodiments of the present disclosure, and theforegoing and other operations and/or functions of the modules in theuser equipment 1700 respectively implement corresponding procedures ofthe methods in FIG. 7 and FIG. 9 to FIG. 14. For brevity, details arenot described herein again.

Therefore, according to the user equipment in this embodiment of thepresent disclosure, through configuration, uplink control informationrelated to a cell in a first SCG of user equipment is transmitted byusing a PUCCH of a first cell, where the first cell belongs to a secondSCG of the user equipment, and/or data transmission on at least one cellin the first SCG is processed by using a layer 2 functional entitylocated in the second SCG, so that a quantity of parameters maintainedby the user equipment can be reduced, thereby reducing complexity of theuser equipment.

In addition, through configuration, the uplink control informationrelated to the cell in the first SCG is transmitted by using the PUCCHof the first cell, avoiding an excessively high power requirement on theuser equipment when transmission is performed on a large quantity ofphysical uplink channels simultaneously, and further improvingfeasibility of a system.

FIG. 22 shows user equipment 1800 provided by another embodiment of thepresent disclosure. The user equipment 1800 includes a receiver 1810configured to receive first configuration indication information sent bya network device, where the first configuration indication informationis used to indicate at least one type of the following configuration, ina data transmission process in at least one cell in a first cell groupof the user equipment, generating an encryption key by using a securityconfiguration parameter of a second cell group of the user equipment, orin a data transmission process in at least one cell in the first cellgroup, performing uplink timing adjustment by using a timing advancevalue of a second cell group of the user equipment, and a processor 1820configured to configure the first cell group according to the firstconfiguration indication information received by the receiver 1810.

Therefore, according to the network device in this embodiment of thepresent disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

It should be understood that in this embodiment of the presentdisclosure, the processor 1820 may be a central processing unit (CPU),or the processor 1820 may be another general purpose processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field-programmable gate array (FPGA), or anotherprogrammable logic device, discrete gate or transistor logic device, ordiscrete hardware component. The general purpose processor may be amicroprocessor or the processor may be any conventional processor or thelike.

The network device may further include a memory. The memory may includea read-only memory and a random access memory and provide an instructionand data to the processor 1820. A part of the memory may further includea non-volatile random access memory. For example, the memory may furtherstore device type information.

The network device may further include a bus system. In addition toincluding a data bus, the bus system may further include a power bus, acontrol bus, a state signal bus, and the like. However, for cleardescription, all buses are marked as the bus system in the figure.

In an implementation process, steps of the foregoing methods may beaccomplished by using an integrated logic circuit of hardware in theprocessor 1820 or an instruction in a form of software. The steps of themethod that are disclosed in the embodiments of the present disclosuremay be directly performed and completed by a hardware processor orperformed and completed by a combination of hardware and softwaremodules in the processor. The software module may be located in a maturestorage medium in the art, such as a random access memory, a flashmemory, a read-only memory, a programmable read-only memory, an electricerasable programmable memory, or a register. The storage medium islocated in the memory, and the processor 1820 reads information in thememory and completes the steps in the foregoing methods in combinationwith hardware of the processor 1820. To avoid repetition, details arenot described herein again.

Optionally, the first cell group and the second cell group areassociated with a same serving base station of the user equipment.

In another optional embodiment, the second cell group is a MCG or a SCG.

In another optional embodiment, serving base stations of the userequipment include a MeNB and at least one SeNB. The second cell group isa SCG, and the first cell group and the second cell group are bothassociated with a SeNB of the user equipment.

In another optional embodiment, the security configuration parameterincludes at least one of the following parameters a SCG counter, a SCGintermediate key, an index value of a SCG intermediate key, or a serialnumber of a SCG intermediate key.

In another optional embodiment, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, generating an encryption key byusing a security configuration parameter of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate processing data transmission on the at least onecell in the first cell group by using a Packet Data Convergence Protocolentity located in the second cell group.

In this case, the processor 1820 is further configured to, according tothat the data transmission on the at least one cell in the first cellgroup is processed by using the Packet Data Convergence Protocol entitylocated in the second cell group, which is indicated in the firstconfiguration indication information, determine to generate, in the datatransmission process in the at least one cell in the first cell group,an encryption key by using a security configuration parameter of thesecond cell group of the user equipment.

In another optional embodiment, that the first configuration indicationinformation is used to indicate, in a data transmission process in atleast one cell in the first cell group, performing uplink timingadjustment by using a timing advance value of a second cell group of theuser equipment includes the first configuration indication informationis used to indicate that the first cell group of the user equipment andthe second cell group of the user equipment belong to a same TAG, or thefirst configuration indication information is used to indicate that aPSCell in the first cell group of the user equipment and a PSCell or aPCell in the second cell group of the user equipment belong to a sameTAG.

In this case, the processor 1820 is further configured to, according tothat the first cell group and the second cell group belong to the sameTAG or the PSCell in the first cell group and the PSCell or the PCell inthe second cell group belong to the same TAG, which is indicated in thefirst configuration indication information, determine to perform, in thedata transmission process in the at least one cell in the first cellgroup, uplink timing adjustment by using the timing advance value of thesecond cell group of the user equipment.

In another optional embodiment, the receiver 1810 is further configuredto receive second configuration indication information sent by thenetwork device, where the second configuration indication information isused to indicate a random access resource allocated by the networkdevice to the second cell group.

Correspondingly, the processor is further configured to perform a randomaccess process in the second cell group according to the secondconfiguration indication information received by the receiver 1810, toobtain a timing advance value of the second cell group.

In this case, the user equipment further includes a transceiverconfigured to communicate with the serving base station of the userequipment in the first cell group according to the timing advance valueof the second cell group that is obtained by the random access unit.

In another optional embodiment, the user equipment 1800 further includesa transmitter configured to send a configuration complete message to thenetwork device.

The user equipment 1800 according to this embodiment of the presentdisclosure may correspond to the user equipment in the communicationmethods according to the embodiments of the present disclosure, and theforegoing and other operations and/or functions of the modules in theuser equipment 1800 respectively implement corresponding procedures ofthe methods in FIG. 8 to FIG. 14. For brevity, details are not describedherein again.

Therefore, according to the network device in this embodiment of thepresent disclosure, through configuration, in a data transmissionprocess in at least one cell in a first cell group of user equipment, anencryption key is generated by using a security configuration parameterof a second cell group of the user equipment, and/or in a datatransmission process in at least one cell in the first cell group,uplink timing adjustment is performed by using a timing advance value ofthe second cell group, so that the user equipment does not need tomaintain a large quantity of security configuration parameters or timingadvance values, thereby reducing complexity of the user equipment, andimproving feasibility of a system.

In addition, through configuration, in the data transmission process inthe at least one cell in the first cell group, uplink timing adjustmentis performed by using the timing advance value of the second cell groupof the user equipment, so that the user equipment can directlycommunicate with a network side without performing a random accessprocess in the first cell group, thereby reducing system resources andreducing power consumption of the user equipment.

An embodiment of the present disclosure further provides acommunications system. The communications system includes user equipmentand at least one serving base station of the user equipment, wheremultiple cell groups are configured for the user equipment, and a firstserving base station in the at least one serving base station of theuser equipment is associated with at least two cell groups of themultiple cell groups.

Optionally, the multiple cell groups include a first SCG and a secondcell group. The second cell group is a MCG or a SCG, and the first SCGand the second cell group meet at least one type of the followingconfiguration transmitting uplink control information related to a cellin the first SCG by using a PUCCH of a first cell, where the first cellbelongs to a second cell group of the user equipment, processing datatransmission on at least one cell in the first SCG by using a layer 2functional entity located in the second cell group, processing datatransmission on at least one cell in the first SCG by using a securityconfiguration parameter of the second cell group of the user equipment,or processing data transmission on at least one cell in the first SCG byusing a timing advance value of the second cell group of the userequipment.

A quantity of the at least one serving base station may be one. In thiscase, the UE may establish a connection only to one base station. Thebase station may configure one MCG and optionally, one or more SCGs forthe UE.

A quantity of the at least one serving base station may also bemultiple. For example, the at least one serving base station includesone MeNB and one SeNB. In this case, the MeNB is connected to the SeNBby using an X2 interface, and the UE may establish connections to theMeNB and the SeNB and then, may configure one MCG and one or more SCGsfor the UE by using the MeNB and the SeNB. For another example, the atleast one serving base station may include one MeNB and multiple SeNBs.The MeNB is connected to the SeNB by using an X2 interface, and theSeNBs are connected to each other by using an X2 interface. In thiscase, the UE may establish a connection to the MeNB and connections tothe multiple SeNBs, and then, may configure one MCG and one or more SCGsfor the UE by using the MeNB and the multiple SeNBs.

The second cell group is a MCG or a SCG. In an optional embodiment, theat least two SCGs include the second cell group.

In another optional embodiment, the first SCG and the second cell groupare associated with a same serving base station of the user equipment.

In another optional embodiment, a quantity of the at least one servingbase station of the user equipment is one, and multiple cell groups ofthe user equipment are all associated with the serving base station ofthe user equipment.

In another optional embodiment, the at least one serving base station ofthe user equipment includes a MeNB and at least one SeNB. The MeNB isassociated with the MCG, and each of the at least one SeNB is associatedwith one or more SCGs in the at least two SCGs.

For example, N cell groups may be configured for the user equipment. TheN cell groups include a MCG and (N-1) SCGs. N is an integer greater than2. If the user equipment has only one serving base station, the N cellgroups may be all associated with the serving base station of the userequipment. If the user equipment has one MeNB and at least one SeNB, theMeNB may be associated with a MCG and zero or at least one SCG in the Ncell groups. Each SeNB may be associated with zero or at least one SCGin the (N-1) SCGs. This embodiment of the present disclosure is notlimited thereto.

In an embodiment, the at least one serving base station may include thenetwork device 1100 shown in FIG. 15, and the user equipment may be theuser equipment 1300 shown in FIG. 17. Alternatively, the at least oneserving base station may include the network device 1200 shown in FIG.16, and the user equipment may be the user equipment 1400 shown in FIG.18.

In another optional embodiment, the at least one serving base stationmay include the network device 1500 shown in FIG. 19, and the userequipment may be the user equipment 1700 shown in FIG. 21.Alternatively, the at least one serving base station may include thenetwork device 1600 shown in FIG. 20, and the user equipment may be theuser equipment 1800 shown in FIG. 22.

It should be understood that, the term “and/or” in this embodiment ofthe present disclosure describes only an association relationship fordescribing associated objects and represents that three relationshipsmay exist. For example, A and/or B may represent the following threecases. Only A exists, both A and B exist, and only B exists. Inaddition, the character “/” in this specification generally indicates an“or” relationship between the associated objects.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, method steps and units may be implemented by electronichardware, computer software, or a combination thereof. To clearlydescribe the interchangeability between the hardware and the software,the foregoing has generally described steps and compositions of eachembodiment according to functions. Whether the functions are performedby hardware or software depends on particular applications and designconstraint conditions of the technical solutions. A person of ordinaryskill in the art may use different methods to implement the describedfunctions for each particular application, but it should not beconsidered that the implementation goes beyond the scope of the presentdisclosure.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, reference may bemade to a corresponding process in the foregoing method embodiments, anddetails are not described herein again.

In the several embodiments provided in the present application, itshould be understood that the disclosed system, apparatus, and methodmay be implemented in other manners. For example, the describedapparatus embodiment is merely exemplary. For example, the unit divisionis merely logical function division and may be other division in actualimplementation. For example, multiple units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented through some interfaces, indirect couplings or communicationconnections between the apparatuses or units, or electrical connections,mechanical connections, or connections in other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on multiplenetwork units. A part or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments of the present disclosure.

In addition, functional units in the embodiments of the presentdisclosure may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

When the integrated unit is implemented in the form of a softwarefunctional unit and sold or used as an independent product, theintegrated unit may be stored in a computer-readable storage medium.Based on such an understanding, the technical solutions of the presentdisclosure essentially, or the part contributing to the prior art, orall or a part of the technical solutions may be implemented in the formof a software product. The software product is stored in a storagemedium and includes several instructions for instructing a computerdevice (which may be a personal computer, a server, or a network device)to perform all or a part of the steps of the methods described in theembodiments of the present disclosure. The foregoing storage mediumincludes any medium that can store program code, such as a USB flashdrive, a removable hard disk, a read-only memory (ROM), a random accessmemory (RAM), a magnetic disk, or an optical disc.

The foregoing descriptions are merely specific embodiments of thepresent disclosure, but are not intended to limit the protection scopeof the present disclosure. Any modification or replacement readilyfigured out by a person skilled in the art within the technical scopedisclosed in the present disclosure shall fall within the protectionscope of the present disclosure. Therefore, the protection scope of thepresent disclosure shall be subject to the protection scope of theclaims.

1. A communication method implemented by a user equipment, comprising: receiving first configuration indication information from a network device, wherein the first configuration indication information indicates instructions to generate an encryption key with a security configuration parameter of a second cell group associated with the user equipment; performing a data transmission process with a cell in a first cell group; and configuring the first cell group according to the first configuration indication information.
 2. The communication method of claim 1, wherein the second cell group associated with the user equipment is a master cell group or a secondary cell group.
 3. The communication method of claim 1, wherein the security configuration parameter comprises at least one of a secondary cell group counter, a secondary cell group intermediate key, an index value of the secondary cell group intermediate key, or a serial number of the secondary cell group intermediate key.
 4. The communication method of claim 1, wherein when the first configuration indication information instructs to generate the encryption key with the security configuration parameter of a-the second cell group in association with the user equipment, the method further comprises processing the data transmission process on the cell in the first cell group using a packet data convergence protocol (PDCP) entity located in the second cell group.
 5. (canceled)
 6. The communication method of claim 1, further comprising: receiving second configuration indication information from the network device, wherein the second configuration indication information indicates a random access resource from the network device to the second cell group of the user equipment; performing a random access process in the second cell group according to the second configuration indication information to obtain the timing advance value of the second cell group; and communicating with a serving base station ef associated with the user equipment in the first cell group according to the timing advance value of the second cell group.
 7. A device, comprising: a processor; and a memory coupled to the processor and storing instructions that, when executed by the processor, cause the device to be configured to: allocate a first cell group to a user equipment; and send first configuration indication information to the user equipment, wherein the first configuration indication information indicates instructions to generate an encryption key with a security configuration parameter of a second cell group associated with the user equipment in a data transmission process with a cell in the first cell group.
 8. The device of claim 7, wherein the first cell group and the second cell group are associated with a same serving base station of the user equipment.
 9. The device of claim 7, wherein the second cell group of the user equipment is a master cell group or a secondary cell group.
 10. The device of claim 7, wherein the security configuration parameter comprises at least one of a secondary cell group counter, a secondary cell group intermediate key, an index value of the secondary cell group intermediate key, or a serial number of the secondary cell group intermediate key.
 11. The device of claim 7, wherein when the first configuration indication information instructs to generate the encryption key with the security configuration parameter of the second cell group associated with the user equipment in the data transmission process in a cell in the first cell group, the instructions further cause the device to be configured to process the data transmission process on the cell in the first cell group using a packet data convergence protocol (PDCP) entity located in the second cell group.
 12. (canceled)
 13. The device of claim 7, wherein the device is a first secondary base station associated with both the first cell group and the second cell group, and wherein the user equipment has at least two serving base stations comprising a master base station and the first secondary base station, wherein the instructions further cause the device to be configured to: receive second configuration indication information from the master base station and allocate the first cell group to the user equipment before sending the first configuration indication information to the user equipment; and determine, according to the second configuration indication information, to allocate the first cell group to the user equipment.
 14. A device, comprising: a processor; and a memory coupled to the processor and storing instructions that, when executed by the processor, cause the device to be configured to: receive first configuration indication information from a network device, wherein the first configuration indication information instructs to generate an encryption key with a security configuration parameter of a second cell group associated with the device; perform a data transmission process with a cell in a first cell group; and configure the first cell group according to the first configuration indication information.
 15. The device of claim 14, wherein the first cell group and the second cell group are associated with a same serving base station for the device.
 16. The device of claim 14, wherein the second cell group associated with the device is a master cell group or a secondary cell group.
 17. The device of claim 14, wherein the security configuration parameter comprises at least one of a secondary cell group counter, a secondary cell group intermediate key, an index value of the secondary cell group intermediate key, or a serial number of the secondary cell group intermediate key.
 18. The device of claim 14, wherein when the first configuration indication information instructs to generate the encryption key with the security configuration parameter of the second cell group associated with the device the instructions further cause the device to be configured to process the data transmission process on the cell in the first cell group using a packet data convergence protocol (PDCP) entity located in the second cell group.
 19. (canceled)
 20. The device of claim 14, wherein the instructions further cause the device to be configured to: receive second configuration indication information from the network device, wherein the second configuration indication information indicates a random access resource from the network device to the second cell group of the device; and perform a random access process in the second cell group according to the second configuration indication information received, to obtain the timing advance value of the second cell group; and communicate with a serving base station associated with the device in the first cell group according to the timing advance value of the second cell group. 